A double-layered roll-pressed binder-free supercapacitor electrode and a preparation method thereof

Abstract

The application provides a double-layer roll-pressed binder-free supercapacitor electrode and a preparation method thereof. A metal foam material is placed into a dilute hydrochloric acid or sodium hydroxide solution, soaked under ultrasonic assistance, then cleaned and dried to obtain a metal foam material with a rough surface corrosion; the metal foam material with a rough surface corrosion is soaked in a PEI aqueous solution, and ultrasonic treatment is performed to obtain a modified metal foam material with a dense pore and a binding property; MWCNT is stirred and dispersed in the PEI aqueous solution to obtain a dispersion A, the modified metal foam material is placed into the dispersion A, and standing is performed to obtain a modified MWCNT-loaded porous metal foam material; the capacitive activated carbon is added into deionized water, and stirring is performed to obtain a dispersion B; the dispersion B is added into the modified MWCNT-loaded porous metal foam material to perform a suction filtration operation, and an activated carbon-loaded electrode material is obtained, and after drying, an electrode sheet is obtained; two electrode sheets with the same shape are adhered and roll-pressed to obtain the double-layer roll-pressed binder-free supercapacitor electrode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrochemical electrode material preparation, in particular to a double-layer roller-pressed binder-free supercapacitor electrode and a preparation method thereof. BACKGROUND

[0002] In the field of supercapacitors, the performance of the electrode is one of the key factors affecting the overall performance of the supercapacitor. In the preparation process of traditional supercapacitor electrodes, adhesives such as polytetrafluoroethylene (PVDF), polytetrafluoroethylene (PTEF), cellulose nanofiber (CNF), styrene-butadiene rubber (SBR) + polyacrylic acid, etc. are usually used to ensure the close combination between electrode materials. However, the addition of adhesives not only increases the weight of the electrode, reduces the electron transfer rate, and thus reduces the overall energy density. It may also adversely affect the electrical conductivity and electrochemical performance of the electrode. Therefore, it is of great significance to study the preparation method of binder-free supercapacitor electrodes.

[0003] In recent years, researchers have been constantly exploring the preparation techniques and methods of binder-free electrodes to improve the performance of supercapacitors. For example: many studies grow active electrode materials on metal substrates, thereby achieving the use of binder-free, such as application number: CN201510706762.8 (Preparation method of metal-graphene composite porous electrode material), CN202310744599.9 (Three-dimensional porous binder-free electrode material and its preparation method and application), CN202110433457.1 (Method for preparing nickel-cobalt double-metal hydroxide@graphene@foam nickel composite material without alkali agent) and the like introduce the growth of active materials on metal current collectors, but there are still some problems in the preparation process, such as harsh high temperature and high pressure conditions, low yield, high cost, and complex preparation process. Therefore, it is of great practical application value to develop a simple, efficient, and economical binder-free supercapacitor electrode preparation method, and it is an effective method to make the electrode material itself realize close combination through physical or chemical methods. SUMMARY

[0004] The purpose of the present application is to provide a double-layer roller-pressed binder-free supercapacitor electrode and a preparation method thereof, to overcome the problem of reduced electrochemical activity caused by the addition of adhesives in the electrode material of the prior art, and the problem of harsh technical conditions and complex preparation of the existing binder-free electrode material.

[0005] The present application is realized by the following technical solutions:

[0006] A preparation method of a double-layer roller-pressed binder-free supercapacitor electrode, comprising the following steps:

[0007] (1) Put the metal foam material into dilute hydrochloric acid or sodium hydroxide solution, soak under the assistance of ultrasonic, then clean with distilled water and ethanol respectively for several times under the assistance of ultrasonic, and then vacuum dry to obtain the metal foam material with rough surface corrosion;

[0008] (2) Soak the metal foam material with rough surface corrosion in PEI aqueous solution, and treat with ultrasonic to obtain the modified metal foam material with dense pores and adhesion;

[0009] (3) Stir and disperse MWCNT in PEI aqueous solution to obtain dispersion A, put the modified metal foam material into the dispersion A, and stand to obtain the modified MWCNT-loaded porous metal foam material;

[0010] (4) Add the capacitive activated carbon into deionized water, and stir to obtain dispersion B;

[0011] (5) Put the modified MWCNT-loaded porous metal foam material into a suction filtration device, add the dispersion B to perform suction filtration operation to obtain the activated carbon-loaded electrode material, and then dry to obtain an electrode sheet;

[0012] (6) Paste and roll two electrode sheets with the same shape to obtain a double-layer roll-pressed binder-free supercapacitor electrode.

[0013] Further, in step (1), the metal foam material is foam nickel or foam aluminum, the thickness of the metal foam material is 0.1mm-1mm, and the pore size is 0.05mm-0.5mm.

[0014] Further, in step (1), the concentration of the dilute hydrochloric acid is 1-5mol / L, and the concentration of the sodium hydroxide solution is 0.01-0.1mol / L.

[0015] Further, in step (1), the soaking under the assistance of ultrasonic is performed for 5-60min, and the temperature of vacuum drying is 60℃.

[0016] Further, in step (2), the molecular weight of PEI is 2000-10000M.W., the mass concentration of the PEI aqueous solution is 1%-10%, and the ultrasonic treatment time is 30min.

[0017] Further, in step (3), the mass concentration of the PEI aqueous solution is 1%, 0.01-1 parts of MWCNT is added into 100 parts of the PEI aqueous solution according to the mass fraction, and the standing time is 6-12h.

[0018] Further, in step (4), the particle size of the capacitive activated carbon is 50-200mesh, 1-10 parts of the capacitive activated carbon is added into 1000 parts of deionized water according to the mass fraction, and the stirring time is 1-3h.

[0019] Further, the drying temperature in step (5) is 90 DEG C, and the drying time is 1-3h.

[0020] Further, in step (6), when the two electrode sheets with the same shape are attached, the two electrode sheets are attached with the active carbon loaded surface and are rolled, and the thickness of the electrode sheet is controlled to be 0.08mm-0.6mm after rolling. 。

[0021] A double-layer rolled binder-free supercapacitor electrode is prepared by the preparation method.

[0022] Compared with the prior art, the present application has the following beneficial technical effects:

[0023] The present application firstly increases the connection sites and adhesion of the active material by modifying the current collector, then increases the specific capacity by uniformly loading more active material in the three-dimensional porous current collector through the simple step of suction filtration, and further improves the adhesion of the electrode by preventing the active material from falling off through the double-layer rolling method. Based on this, the present application realizes the close combination of the electrode active material and the conductive additive by physical and chemical methods, and prepares the supercapacitor electrode material without adding binder. Compared with the existing binder-free technology based on in-situ growth of active material on the substrate, the method of the present application is simple and easy to operate, the raw materials are widely available, and the method has a wide application prospect. Specifically:

[0024] (1) The preparation method is simple, the polymer PEI adhesion and the chelation of heavy metals can be more easily combined with the etched foam nickel, the modified foam nickel can form a sticky and dense network structure inside. At the same time, the high adhesion and adsorption of PEI make the active material more easily combined with the foam nickel.

[0025] (2) Low cost, using commercial mature capacitor active carbon material, through the process of reduced pressure suction filtration, the capacitor active carbon material is more easily combined to the porous network inside the foam nickel, and the problem of poor dispersion of the electrode active carbon material in water is solved.

[0026] (3) The high-temperature drying process further crosslinks the PEI polymer chain, and then the double-layer rolling process makes the foam nickel substrate and the active material more closely combined, without the need for binder to improve the internal conductivity and energy density of the electrode. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced below, and the following drawings only show some embodiments of the present application, and should not be considered as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0028] Figure 1 A schematic diagram of the preparation process of the double-layer roll-pressed binder-free supercapacitor electrode.

[0029] Figure 2 A charge-discharge curve diagram of the double-layer roll-pressed binder-free electrode material in Example 1 at 1 A / g. DETAILED DESCRIPTION

[0030] The application will be described in detail as follows:

[0031] A preparation method of a double-layer roll-pressed binder-free supercapacitor electrode, comprising the following steps:

[0032] (1) Surface corrosion treatment of porous metal foam material, metal foam material (foamed nickel or foamed aluminum) with a thickness of 0.1 mm to 1 mm and a pore size of 0.05 mm to 0.5 mm is placed in 1-5 mol / L dilute hydrochloric acid or 0.01-0.1 mol / L sodium hydroxide solution for ultrasonic immersion for 5-60 min. Ultrasonic cleaning with distilled water, ethanol respectively three times, remove the surface residual acid and other pollutants, and then vacuum drying at 60℃, to obtain a surface corrosion rough metal foam material.

[0033] (2) Modified porous metal foam material, take multiple surface corrosion rough metal foam materials with the same size, immerse in 1%-10% polyethyleneimine (PEI, molecular weight 2000-10000 M.W.) aqueous solution, ultrasonic for 30 min, to obtain a modified metal foam material with dense pores and adhesion.

[0034] (3) According to the mass fraction, take 0.01-1 parts of multi-walled carbon nanotubes (MWCNT) and stir to disperse in 100 parts of 1% PEI aqueous solution to prepare dispersion A. Put the modified metal foam material in step (2) into dispersion A and stand for 6-12 hours to obtain a modified MWCNT-loaded porous metal foam material.

[0035] (4) According to the mass fraction, take 1-10 parts of capacitive activated carbon with a particle size of 50-200 mesh and add to 1000 parts of deionized water, stir for 1-3 h to obtain dispersion B.

[0036] (5) Put the modified MWCNT-loaded porous metal foam material in step (3) into a suction filtration device padded with filter paper, add dispersion B and perform suction filtration operation to obtain an activated carbon-loaded electrode material, and dry at 90℃ for 1-3 h to obtain an electrode sheet.

[0037] (6) Take the two electrode pieces of the same shape obtained in step (5), and roll them together with the active carbon-loaded surfaces attached. The thickness of the electrode pieces after rolling is controlled to be 0.08 mm to 0.6 mm, and a double-layer rolled binderless electrode material is obtained. Electrochemical testing is performed at a current density of 1 A / g, and the electrode is charged and discharged in a range of 0-1.2 V. The specific capacitance is 31.7-89.4 F / g.

[0038] The present application first increases the connection sites and adhesion of active materials by modifying the current collector, then increases the specific capacity by uniformly loading more active materials in the three-dimensional porous current collector through a simple filtration step, and further improves the adhesion of the electrode by preventing the active materials from falling off through a double-layer rolling method. Based on this, the present application realizes the close combination of the electrode active material and the conductive additive by physical and chemical methods, and prepares a supercapacitor electrode material without adding a binder. Compared with the existing binderless technology based on in-situ growth of active materials on the substrate, the method of the present application is simple and easy to implement, the raw materials are widely available, and has a broad application prospect.

[0039] The embodiments of the present application will be described in detail below with reference to the examples. The examples are preferred embodiments of the present application, and cannot limit the scope of the present application. In the following examples, the methods and experimental apparatuses used are conventional methods and apparatuses unless otherwise specified.

[0040] Example 1

[0041] A preparation method of a double-layer rolled binderless supercapacitor electrode, comprising the following steps:

[0042] (1) Surface etching treatment of porous nickel foam, the thickness of the porous nickel foam is 0.1 mm, and the pore size distribution is 0.05 mm to 0.5 mm. The porous nickel foam is immersed in 1 mol / L dilute hydrochloric acid under ultrasonic for 30 min. Ultrasonic cleaning is performed in distilled water and ethanol for three times respectively to remove the residual acid and other contaminants on the surface. Vacuum drying is performed at 60°C to obtain a porous nickel foam with a rough surface.

[0043] (2) Modification of porous nickel foam, a plurality of porous nickel foams with the same size and surface treatment are immersed in a 2% (molecular weight 10000 M.W.) PEI aqueous solution under ultrasonic for 30 min to obtain a modified porous nickel foam with a dense and porous structure and adhesion.

[0044] (3) According to the mass fraction, 0.01 parts of MWCNT with a mass fraction of 1% is stirred and dispersed in 100 parts of PEI aqueous solution to prepare a dispersion solution A. The modified porous nickel foam obtained in step (2) is placed in the solution A and left for 6 h to obtain a modified porous nickel foam loaded with MWCNT.

[0045] (4) Take 1 part of capacitive activated carbon with a particle size of 50 mesh by mass fraction, add it to 1000 parts of deionized water, stir for 3h, and obtain capacitive activated carbon dispersion B.

[0046] (5) Put the modified MWCNT-loaded porous nickel foam described in step (3) into a suction filtration device padded with filter paper, add dispersion B, and perform suction filtration operation to obtain activated carbon-loaded electrode material. After drying at 90°C for 1h, an electrode sheet is obtained.

[0047] (6) Take two electrode sheets of the same shape described in step (5), and roll them together with the side loaded with more activated carbon to obtain a double-layer roll-pressed binder-free electrode material with a thickness of 0.08mm. As shown in the accompanying Figure 2 , the electrochemical test is charged and discharged in the range of 0-1.2V at a current density of 1A / g, and the specific capacitance is 58.3F / g.

[0048] Example 2

[0049] A method for preparing a double-layer roll-pressed binder-free supercapacitor electrode, comprising the following steps:

[0050] (1) Surface corrosion treatment of porous nickel foam, put the porous nickel foam with a thickness of 1mm and a pore size distribution of 0.05mm-0.5mm into 5mol / L dilute hydrochloric acid and soak for 60min under ultrasonic. Ultrasonic cleaning in distilled water and ethanol for three times respectively to remove surface residual acid and other contaminants, and vacuum drying at 60°C to obtain surface-roughened foam nickel.

[0051] (2) Modification of porous nickel foam, take multiple foam nikkels of the same size after surface treatment, soak in a 10% (molecular weight 2000M.W.) PEI aqueous solution, and ultrasonic for 30min to obtain dense and porous modified foam nickel with adhesion.

[0052] (3) According to the mass fraction, take 1 part of MWCNT and stir it in 100 parts of 1% PEI aqueous solution to prepare dispersion A. Put the modified foam nickel in solution A and stand for 12h to obtain modified MWCNT-loaded porous nickel foam.

[0053] (4) Take 10 parts of capacitive activated carbon with a particle size of 200 mesh by mass fraction, add it to 1000 parts of deionized water, stir for 1h, and obtain capacitive activated carbon dispersion B.

[0054] (5) Put the modified MWCNT-loaded porous nickel foam described in step (3) into a suction filtration device padded with filter paper, add dispersion B, and perform suction filtration operation to obtain activated carbon-loaded electrode material. After drying at 90°C for 3h, an electrode sheet is obtained.

[0055] (7)Take two electrode pieces of the same shape as described in step (5), and roll the electrode pieces with the side having more activated carbon loaded on it to a thickness of 0.6 mm to obtain a double-layer rolled binderless electrode material. Electrochemical testing was performed at a current density of 1 A / g in the range of 0-1.2 V, and the specific capacitance was 86.5 F / g.

[0056] Example 3

[0057] A method for preparing a double-layer rolled binderless supercapacitor electrode includes the following steps:

[0058] (1) Surface corrosion treatment of porous aluminum foam. Foam aluminum with a thickness of 0.5 mm and a pore size distribution of 0.05 mm-0.5 mm was immersed in a 0.01 mol / L sodium hydroxide solution under ultrasonic treatment for 5 min. The surface was cleaned three times in distilled water and ethanol under ultrasonic treatment to remove residual acid and other contaminants, and then dried in a vacuum at 60°C to obtain a foam aluminum with a rough surface.

[0059] (2) Modified porous aluminum foam. A plurality of foam aluminums of the same size were immersed in a 10% (molecular weight 5000 M.W.) PEI aqueous solution under ultrasonic treatment for 30 min to obtain a modified porous foam aluminum with high density and adhesion.

[0060] (3) According to the mass fraction, 0.5 parts of MWCNT were stirred in 100 parts of a 1% PEI aqueous solution to prepare dispersion solution A. The modified foam aluminum of step (2) was placed in solution A and allowed to stand for 8 h to obtain a modified MWCNT-loaded porous foam aluminum.

[0061] (4) According to the mass fraction, 5 parts of activated carbon with a particle size of 100 mesh were added to 1000 parts of deionized water and stirred for 2 h to obtain an activated carbon dispersion solution B.

[0062] (5) The modified MWCNT-loaded porous foam aluminum of step (3) was placed in a suction filtration device lined with filter paper, and the dispersion solution B was added to perform suction filtration to obtain an activated carbon-loaded electrode material, which was dried at 90°C for 1 h to obtain an electrode piece.

[0063] (6) Take two electrode pieces of the same shape as described in step (5), and roll the electrode pieces with the side having more activated carbon loaded on it to a thickness of 0.4 mm to obtain a double-layer rolled binderless electrode material. Electrochemical testing was performed at a current density of 1 A / g in the range of 0-1.2 V, and the specific capacitance was 45.4 F / g.

[0064] Example 4

[0065] A method for preparing a double-layer rolled binderless supercapacitor electrode includes the following steps:

[0066] (1) Surface corrosion treatment of porous aluminum foam, the thickness of 1 mm, pore size distribution in 0.05 mm ~ 0.5 mm of aluminum foam, put into 0.1 mol / L sodium hydroxide solution under ultrasonic immersion 6 min. In distilled water, ethanol were ultrasonic cleaning three times, respectively, to remove the surface of the remaining acid and other pollutants, at 60°C vacuum drying, get surface corrosion roughness of aluminum foam.

[0067] (2) Modified porous aluminum foam, take multiple size same after surface treatment foam, soak in mass concentration of 1% (molecular weight 10000 M.W.) PEI aqueous solution, ultrasonic 30 min, get dense porous modified foam with adhesion.

[0068] (3) According to the mass fraction, take 0.1 parts of MWCNT stirring in 100 parts of mass concentration of 1% PEI aqueous solution, preparation of dispersion A. The modified foam of step (2) is put into solution A and placed for 8 h to obtain the modified porous foam loaded with MWCNT.

[0069] (4) According to the mass fraction, take 8 parts of capacitive activated carbon with particle size of 100 mesh and add them to 1000 parts of deionized water, stir for 2 h to obtain the dispersion B of capacitive activated carbon.

[0070] (5) The modified porous foam loaded with MWCNT of step (3) is put into a suction filtration device padded with filter paper, and the dispersion B is added for suction filtration operation to obtain the electrode material loaded with activated carbon. After drying at 90°C for 2 h, the electrode sheet is obtained.

[0071] (6) Take two electrode sheets of the same shape as described in step (5), and roll the electrode sheets with the side loaded with more activated carbon to a thickness of 0.5 mm to obtain the double-layer rolled binder-free electrode material. Electrochemical test, charge and discharge in the range of 0-1.2V at a current density of 1A / g, and the specific capacitance is 56.1F / g.

[0072] Example 5

[0073] A method for preparing a double-layer rolled binder-free supercapacitor electrode, comprising the following steps:

[0074] (1) Surface corrosion treatment of porous nickel foam, the thickness of 1 mm, pore size distribution in 0.05 mm ~ 0.5 mm of aluminum foam, put into 2 mol / L dilute hydrochloric acid under ultrasonic immersion 30 min. In distilled water, ethanol were ultrasonic cleaning three times, respectively, to remove the surface of the remaining acid and other pollutants, at 60°C vacuum drying, get surface corrosion roughness of aluminum foam.

[0075] (2) Modified porous nickel foam, take multiple same size after surface treatment of foam nickel, soak in 8% (molecular weight 5000 M.W.) PEI aqueous solution, ultrasonic 30 min, get dense porous modified foam nickel with adhesion.

[0076] (3) According to the mass fraction, take 0.8 parts of MWCNT and stir in 100 parts of 1% PEI aqueous solution to prepare dispersion solution A. Put the modified foam nickel in step (2) into solution A and stand for 12 h to get modified MWCNT loaded porous foam nickel.

[0077] (4) According to the mass fraction, take 8 parts of 200 mesh capacitive activated carbon and add to 1000 parts of deionized water, stir for 2 h to get capacitive activated carbon dispersion B.

[0078] (5) Put the modified MWCNT loaded porous foam nickel in step (3) into a filter paper lined suction filtration device, add dispersion B and perform suction filtration operation to get activated carbon loaded electrode material, which is dried at 90℃ for 1.5 h to get electrode sheet.

[0079] (7) Take two electrode sheets in step (5) with the same shape, roll them together with the side loaded with more activated carbon, and get double-layer rolled binder-free electrode material with a thickness of 0.4 mm. Electrochemical test shows that the specific capacitance is 89.4 F / g at a current density of 1 A / g in the range of 0-1.2 V.

[0080] Example 6

[0081] A method for preparing a double-layer rolled binder-free supercapacitor electrode, comprising the following steps:

[0082] (1) Surface corrosion treatment of porous aluminum foam, put the foam aluminum with a thickness of 1 mm and a pore size distribution of 0.05-0.5 mm into 0.05 mol / L sodium hydroxide solution and soak for 10 min under ultrasonic. Ultrasonic cleaning in distilled water and ethanol for three times respectively to remove surface residual acid and other contaminants, and vacuum drying at 60℃ to get surface corrosion roughened foam aluminum.

[0083] (2) Modified porous aluminum foam, take multiple same size after surface treatment of foam aluminum, soak in 2% (molecular weight 1000 M.W.) PEI aqueous solution, ultrasonic 30 min, get dense porous modified foam aluminum with adhesion.

[0084] (3) According to the mass fraction, take 0.05 parts of MWCNT and stir in 100 parts of 1% PEI aqueous solution to prepare dispersion solution A. Put the modified foam aluminum in step (2) into solution A and stand for 8 h to get modified MWCNT loaded porous foam aluminum.

[0085] (4) 1 part of the activated carbon with a particle size of 100 mesh was added into 1000 parts of deionized water to obtain a dispersion liquid B of the activated carbon by stirring for 2 h.

[0086] (5) The modified porous aluminum foam loaded with MWCNTs in step (3) was placed in a suction filtration device padded with filter paper, and the dispersion liquid B was added to perform a suction filtration operation to obtain an electrode material loaded with activated carbon, and an electrode sheet was obtained by drying at 90°C for 1 h.

[0087] (6) Two electrode sheets with the same shape in step (5) were taken, and the surfaces loaded with more activated carbon were adhered and rolled to obtain a double-layer rolled binder-free electrode material with a thickness of 0.4 mm. Electrochemical tests were performed at a current density of 1 A / g in a charge-discharge range of 0-1.2 V, and the specific capacitance was 31.7 F / g.

[0088] Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make various modifications and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be defined by the claims.

Claims

1. A method for preparing a double-layered roll-pressed binder-free supercapacitor electrode, characterized by, It comprises the following steps: (1) Put the metal foam material into dilute hydrochloric acid or sodium hydroxide solution, soak under the assistance of ultrasonic, then clean with distilled water and ethanol respectively for several times under the assistance of ultrasonic, and then vacuum dry to obtain the metal foam material with rough surface corrosion; (2) Soak the metal foam material with rough surface corrosion in PEI aqueous solution, and treat with ultrasonic to obtain the modified metal foam material with dense pores and adhesion; (3) Stir and disperse MWCNT in PEI aqueous solution to obtain dispersion A, put the modified metal foam material into dispersion A, and stand to obtain the modified MWCNT-loaded porous metal foam material; (4) Add the capacitive activated carbon into deionized water, and stir to obtain dispersion B; (5) Put the modified MWCNT-loaded porous metal foam material into a suction filtration device, add dispersion B to perform suction filtration operation to obtain the activated carbon-loaded electrode material, dry to obtain an electrode sheet; (6) Paste two electrode sheets with the same shape to perform roll pressing to obtain a double-layer roll-pressed binder-free supercapacitor electrode.

2. The method according to claim 1, wherein The metal foam material in step (1) is foam nickel or foam aluminum, the thickness of the metal foam material is 0.1-1 mm, and the pore size is 0.05-0.5 mm.

3. The method according to claim 1, wherein The concentration of the dilute hydrochloric acid in step (1) is 1-5 mol / L, and the concentration of the sodium hydroxide solution is 0.01-0.1 mol / L.

4. The method according to claim 1, wherein In step (1), the soaking under the assistance of ultrasonic is performed for 5-60 min, and the temperature of vacuum drying is 60℃.

5. The method according to claim 1, wherein In step (2), the molecular weight of PEI is 2000-10000 M.W., the mass concentration of the PEI aqueous solution is 1-10%, and the ultrasonic treatment time is 30 min.

6. The method according to claim 1, wherein In step (3), the mass concentration of the PEI aqueous solution is 1%, 0.01-1 parts of MWCNT is added into 100 parts of the PEI aqueous solution according to the mass fraction, and the standing time is 6-12 h.

7. The method according to claim 1, wherein the method is characterized by, In step (4), the particle size of the capacitive activated carbon is 50-200 mesh, 1-10 parts of the capacitive activated carbon is added into 1000 parts of deionized water according to the mass fraction, and the stirring time is 1-3 h.

8. The method according to claim 1, wherein In step (5), the drying temperature is 90℃, and the drying time is 1-3 h.

9. The method according to claim 1, wherein the method is characterized by, In the step (6), when the two electrode plates with the same shape are attached, the two electrode plates are attached with the surface loaded with the activated carbon and then are rolled, and the thickness of the electrode plate is controlled to be 0.08mm-0.6mm 。 10. A double-layered roll-pressed binderless supercapacitor electrode, characterized by, The preparation method is prepared by any one of claims 1-9. The preparation method is prepared by any one of claims 1-9.

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