Dry electrode preparation method of button supercapacitor

Abstract

The invention provides a brand-new preparation method of a button supercapacitor, a preparation method of a conductive adhesive and a dry-method thick carbon film required in the preparation process is redesigned, and the preparation process of gluing, glue drying and glue softening, carbon film punching and carbon film and coating lamination is used. In the whole process, no water is introduced, the dry carbon film is flexibly connected with the shell cover, the high-temperature performance of the product can be greatly improved, the energy consumption generated in the water removal process is reduced, and compared with a traditional process, the product prepared by using the improved method can reduce the total energy consumption by 40%, shorten the production time by 50% and reduce the production cost. And the high-temperature load performance of the product is greatly improved.

Description

Technical Field

[0001] The invention relates to a method for preparing a button supercapacitor, and in particular to a method for preparing a dry electrode of a button supercapacitor. Background Art

[0002] Supercapacitors are high-performance energy storage devices. Their principle is to store energy by fast charging and discharging at the electrode surface-electrolyte interface based on porous carbon, conductive polymers, etc. The emergence of supercapacitors fills the gap between traditional capacitors and batteries. Compared with traditional capacitors, supercapacitors have obvious capacity advantages. Under the same volume, the capacity of supercapacitors can reach thousands of times that of traditional capacitors, and compared with batteries, the power density of supercapacitors can reach hundreds to thousands of times that of lithium batteries.

[0003] At present, supercapacitors on the market mainly have two packaging forms: button type and cylindrical type. The two structural capacitors have different usage scenarios. Button supercapacitors are a type of miniaturized supercapacitors. Compared with cylindrical supercapacitors, button supercapacitors mainly have the advantages of small size, low leakage current, and high standby voltage. However, button supercapacitors have higher internal resistance and weaker high-power discharge capability. Therefore, button supercapacitors are mainly suitable for some low-power devices with strict restrictions on the size of components.

[0004] The main evaluation indicators of supercapacitor performance include: capacity, internal resistance, self-discharge, leakage current, high temperature load, cycle life and other indicators. Among them, high temperature load is an important indicator for evaluating the life of supercapacitors. Usually, the series capacitors are placed in an oven at 70°C and kept in a floating charge state at a set voltage. For conventional products, it is usually required that the internal resistance growth rate of the product is less than 300% and the capacity retention rate is greater than 70% after 1000 hours of high temperature load. The life of existing supercapacitors is mainly affected by materials and processing technology. At present, the high temperature load life of supercapacitors in the industry is only 1000 hours, but through comparative analysis with cylindrical supercapacitors, it is believed that its theoretical life can reach 4000 hours. Regarding the problem that the life of button supercapacitors is generally short, through the dissection of the product, it is analyzed that its life is short, mainly affected by the shedding of the conductive coating and the high water content of the electrode. The shedding of the conductive coating is mainly affected by two aspects: 1) The conductive coating is a rigid structure, and the coating adheres the electrode to the current collector. During the baking process, the expansion and contraction of the electrode will cause the conductive coating to fall off from the current collector; 2) During the sealing process of the button capacitor, the steel shell is subjected to greater stress and undergoes certain deformation, resulting in the shedding and damage of the coating. The reason for the high water content in the electrode is mainly introduced during the preparation of the electrode and the use of the conductive coating.

[0005] Button-type supercapacitors need to fully remove water from the electrodes before assembly. The moisture in the electrodes mainly comes from the carbon film and the conductive coating. For carbon films prepared by the wet method, the energy consumed in the dehydration process accounts for more than 40% of the total energy consumption in the capacitor production process, and the time required for carbon film production accounts for more than 50% of the product production cycle. Summary of the invention

[0006] In view of the above problems, the present invention provides a method for preparing a dry electrode of a button supercapacitor. No moisture is introduced in the whole process, and a flexible conductive adhesive is used, which can solve the problem of coating shedding during the processing.

[0007] To achieve the above object, the technical solution adopted by the present invention is: The dry electrode preparation method of the button supercapacitor of the present invention comprises the following preparation steps: Use CMC as thickener, chlorinated polyolefin resin as binder, and carbon material as conductive filler. After mixing, use double planetary mixer to stir, and then use colloid mill to disperse the materials. The mixed conductive filler accounts for 10-60% of the solid content of the conductive glue. After the materials are stirred, use high-speed shearing equipment to process the materials. Use the high shearing line speed of the equipment to make the materials evenly and finely dispersed to obtain conductive glue. Take activated carbon and conductive carbon and mix them thoroughly, the mass of conductive carbon accounts for 1-10% of the mass of the mixture. After stirring, control the stirring environment temperature at 0-15°C. After the temperature is reached, add PTFE powder, the mass of PTFE accounts for 1-9% of the total weight, and then fully heat the materials, and then perform air flow crushing. During the entire processing process, the temperature of the materials is maintained between 70-150°C; for pressing the dry carbon film, the crushed material in step 2 is rolled, the temperature of the rolling process equipment is 100-190°C, the roller gap is set to 0.5-1.5mm, and the rolling pressure is 100-400N / mm to obtain a carbon film; Prepare button capacitor electrodes, transfer the conductive glue prepared in step 1) to the shell cover by transfer printing, control the thickness of the transferred conductive glue to be between 0.005 and 0.02 mm, and the area to be between 70 and 150% of the electrode area, and use a tunnel furnace for baking, the baking temperature is set at 80 to 180 ° C, and the time is controlled at 1 to 20 min. During the process of punching the carbon film prepared in step 2 onto the shell cover, the temperature of the shell cover needs to be maintained at 80 to 180 ° C. The punch presses the punched carbon film onto the shell cover, the pressure is set to 1 to 10 t, and the pressure holding time is 1 to 20 s. The processed carbon film needs to fit tightly inside the shell cover.

[0008] According to the dry electrode preparation method of the button supercapacitor, in step 1), the carbon material includes two mixtures, one is one or a pair of acetylene black, Ketjen black, Super-P and graphene, and the other is a one-dimensional carbon material, the one-dimensional carbon material is one or a mixture of two of carbon nanotubes (CNTs) and carbon nanofibers (VGCF), and the mass of the one-dimensional carbon material accounts for between 1% and 20% of the mass of the carbon material.

[0009] According to the dry electrode preparation method of the button supercapacitor, in step 1), CMC and chlorinated polyolefin resin are first mixed, and then one or more carbon materials selected from acetylene black, Ketjen black, Super-P and graphene are mixed and stirred. After the material becomes an oily viscous liquid, a one-dimensional carbon material is added and stirring is continued.

[0010] According to the dry electrode preparation method of the button supercapacitor, in step 1), a double planetary mixer is used for stirring, and finally a colloid mill is used to disperse the material, and then a high-speed shearing device is used to process the material, and the high shearing linear speed of the device is utilized to make the material evenly and finely dispersed.

[0011] According to the dry electrode preparation method of the button supercapacitor, in step 1), CMC is first fully dissolved in deionized water, and then a chlorinated polyolefin resin dispersion is added, and a uniform solution is prepared after stirring, and a conductive filler is added to the solution prepared in the previous step, and high-speed stirring and dispersion are performed, and then a high-speed shear mixer is used for processing, and then the filtered material is subjected to low-speed stirring treatment, and then filtered using a filter, and the filtered material is sealed and stored, and taken out when used.

[0012] According to the dry electrode preparation method of the button supercapacitor, in step 2), the conductive carbon and the activated carbon are placed in different ovens for high-temperature dehydration. The temperature of the oven should be set at 100-180°C, and the baking time is 6-12 hours. The timing starts when the center temperature of the material reaches the set value. The activated carbon and the conductive carbon after dehydration are weighed according to the proportion and then stirred.

[0013] According to the dry electrode preparation method of the button supercapacitor, in step 3), the conductive glue is added to the material tank of the equipment, and then the conductive glue is first stirred at a low speed, the stirring speed is controlled below 40 rpm, stirred for 2 to 30 minutes, and then the conductive glue is transferred to the button shell cover.

[0014] According to the dry electrode preparation method of the button supercapacitor, in step 2), the speed ratio of the two rollers of the roller press is 1:2, the electrode piece with edge defects of the carbon film after rolling is cut off, the width of the carbon film after slitting is 220 mm, and the carbon film after slitting is rolled up, and the winding tension is controlled at 1~8N.

[0015] According to the dry electrode preparation method of the button supercapacitor, in step 2), after adding PTFE powder, the material is placed in a preheated blast oven, the temperature of the oven is set at 70~150°C, the temperature at the center of the material is tested, and heating is continued for 0.5~4h after reaching the set temperature. The baked material is added to the screw feeder, the feeding speed is controlled at 4~10kg / h, the material is processed by a jet mill, the crushing pressure of 0.5~0.8MPa is selected, the feeding pressure of the material is selected to be 0.6~0.8MPa, the processing environment temperature is 25±5°C, and the relative humidity needs to be lower than 30%RH.

[0016] According to the dry electrode preparation method of the button supercapacitor, the shell cover and the diaphragm prepared in step 3) are placed in a vacuum oven, the vacuum degree is controlled below -85Kpa, the baking temperature is set to 80~150℃, and the baking time is 4~20h to obtain the required electrode.

[0017] The electrode preparation process of the present invention does not introduce water, and a flexible conductive adhesive is manufactured. During the processing, not only can the problem of coating shedding be solved, but also the voltage retention rate and high-temperature load life of the product can be improved, the energy consumption in the production process can be reduced, and the production cycle of the product can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the appearance diagram of the pole piece produced by the present invention.

[0019] Figure 2 This is an appearance diagram of the conductive adhesive of the present invention.

[0020] Figure 3 The improvement effect comparison of the electrode-assembled button capacitor produced by the present invention in high temperature load test is shown.

[0021] Figure 4 The figure is a comparison of the voltage retention rate improvement effect of the electrode-assembled button capacitor produced by the present invention. DETAILED DESCRIPTION

[0022] The specific contents of the present invention are further described below: This article provides a new preparation method for dry electrode button supercapacitors, which includes the preparation of conductive adhesive used in the processing, dry thick carbon film preparation and electrodes.

[0023] The specific method for preparing a dry electrode button-type supercapacitor according to the present invention comprises the following steps: Step 1), dissolve CMC in deionized water solution. During the stirring process, it is necessary to manually scrape off the undissolved CMC adhering to the stirring equipment to ensure that the added CMC is completely dissolved. The prepared solution is a colorless or light yellow transparent solution. The concentration of CMC needs to be controlled between 0.5~5%. Adjust the concentration of CMC according to the viscosity requirements of the subsequent transfer equipment. It should be noted that in this step, the temperature should be controlled between 15~30℃.

[0024] Step 2), slowly add the chlorinated polyolefin resin dispersion to the CMC aqueous solution, and stir the solution to a uniform solution after the addition is completed. During the addition process, low-speed stirring needs to be maintained. The mass of the added chlorinated polyolefin resin accounts for between 30% and 50% of the solid content of the conductive adhesive.

[0025] Step 3) First add one or more carbon materials from acetylene black, Ketjen black, Super-P, and graphene to the glue prepared in the previous step, use the stirring and dispersing function, and add one or two carbon materials from carbon nanotubes (CNTs) or carbon nanofibers (VGCF) after they are completely dispersed in the glue system. The addition of one-dimensional carbon materials is mainly to form a conductive network and increase the conductivity of the conductive glue. In the first step of adding carbon materials for stirring, it is necessary to use a smaller dispersion speed first. After complete wetting, manually scrape off the material adhering to the stirring paddle, and then use high-speed dispersion to treat the slurry. During the stirring process, add one-dimensional carbon materials after an oily viscous liquid is formed. The conductive filler accounts for 10-60% of the solid content of the conductive glue, and the mass of the one-dimensional carbon material accounts for between 1-20% of the conductive filler.

[0026] Step 4) Add the material obtained in the previous step into the high-speed shear mixer, and use the high shear linear speed of the equipment to make the material evenly and finely dispersed. It is necessary to control the time or number of colloid milling. Too many times or too long time will lead to demulsification problems.

[0027] Step 5), use a low-speed mixer to stir the material processed in the previous step, and control the stirring speed below 20-40 rpm. Use a sieve to filter the stirred material. Select a sieve with the corresponding mesh size according to the material usage scenario. Generally, a sieve with 80-120 mesh can be used.

[0028] Step 6) Place the material prepared in the previous step in a sealed container and store it away from light at a temperature between 5 and 35°C.

[0029] Step 7) Place the conductive carbon and activated carbon in a blast oven for high-temperature dehydration. The oven temperature should be set at 100-180°C. The baking time is 6-12 hours, starting when the center temperature of the material reaches the set value.

[0030] Step 8) Add the baked materials in the previous step to the ribbon mixer in a certain proportion. The mass of the conductive carbon accounts for 1-10% of the mass of the mixed carbon. Adjust according to the oil absorption value of the conductive carbon. The proportion of conductive carbon with high oil absorption value should be appropriately reduced. Set the stirring speed to 30 rpm and stir for 6-12 hours.

[0031] Step 9), add PTFE powder to the ribbon mixer, the mass of PTFE accounts for 1-9% of the total weight. The stirring environment temperature is set to 0-15°C, the temperature needs to be controlled below 10°C before adding PTFE, the speed is set to 30 rpm, and stirring is performed for 4-8 hours.

[0032] Step 10), take out the material that was stirred evenly in the previous step, place it in a preheated blast oven, set the oven temperature at 70~150℃, test the temperature at the center of the material, continue heating for 0.5~4h after reaching the set temperature, add the baked material to the screw feeder, and control the feeding speed at 4~10kg / h. Use an air flow mill to process the material, choose a crushing pressure of 0.5~0.8MPa, and a material feed pressure of 0.6~0.8MPa. The processing environment temperature is 25±5℃, and the relative humidity needs to be lower than 30%RH.

[0033] Step 11), first preheat the roller press, set the temperature to 100~190℃, and when the set temperature is reached and the temperature is stable, adjust the roller gap spacing, set the roller gap spacing to 0.5~1.5mm, and make appropriate adjustments according to the required electrode thickness. After the equipment is stable, add the airflow crushed material into the material trough, and the speed ratio of the two rollers is 1:2. Roll out a continuous self-supporting carbon film under a line pressure of 100~400N / mm, and cut off the electrode with edge defects of the rolled carbon film. The width of the slit carbon film is 220mm, and the slit carbon film is rolled up, and the winding tension is controlled at 1~8N.

[0034] Step 12), add the conductive glue prepared in step 6 to the material tank of the equipment. It should be noted that the conductive glue needs to be stirred at a low speed before use. The stirring speed is controlled below 40 rpm and stirred for 2 to 30 minutes. The material tank of the equipment is stirred with a reciprocating stainless steel stick, and the rubber head of the equipment transfers the conductive glue to the button shell cover.

[0035] Step 13), the shell cover that has completed the transfer operation in the previous step is transferred to a tunnel furnace for baking. The baking temperature is set at 80~180℃, and the time is controlled at 1~20min. The baking time is adjusted according to different temperatures, and the adjustment is based on the removal of moisture in the conductive glue.

[0036] Step 14), punch the rolled carbon film in step 11 into the shell cover prepared in step 13. During the punching process, the shell cover needs to maintain a high temperature. The pressure between the punched carbon film and the shell cover is set to 1~10t, and the holding time is 1~20s. The processed carbon film can fit tightly inside the shell cover. In this step, you can choose a product with a sealing ring injection molded on the shell cover. Compared with the product with a sealing ring separated from the shell cover, the use of an injection molded shell cover can greatly reduce the risk of liquid leakage of the product.

[0037] Step 15), place the shell cover and diaphragm and other materials prepared in the previous step in a vacuum oven, control the vacuum degree below -85Kpa, set the baking temperature to 80~150℃, and the baking time to 4~20h.

[0038] Step 16), assemble the materials after dehydration in the previous step into a button capacitor.

[0039] The following is a further description of the embodiments of the present invention by means of specific examples. Example

[0040] The dry electrode preparation method of the button-type supercapacitor of the present invention uses the following raw materials: CMC, acetylene black, Ketjen black, Super-P, graphene, carbon nanotubes (CNTs), carbon nanofibers (VGCF), chlorinated polyolefin resin dispersion, deionized water, activated carbon, conductive carbon, button shell cover, electrolyte, polypropylene diaphragm, and PTFE binder.

[0041] The first step is to add an appropriate amount of deionized water to the double planetary mixer, take an appropriate amount of CMC and evenly sprinkle it in the deionized water. The concentration of CMC is 4.0%. The stirring parameters are set as follows: revolution 30r / min, rotation 1800r / min, stirring time 240min, and the temperature of the material is controlled at 25°C. Within 60 minutes of initial stirring, it is necessary to observe whether CMC has problems adhering to the stirring paddle. If there is a problem, the material needs to be scraped off manually. After stirring, it is necessary to vacuum to remove bubbles in the solution, and the vacuum degree is controlled below -90kPa for 60 minutes. After stirring, the prepared CMC solution should be a colorless to light yellow transparent solution, and no undissolved CMC particles should appear in the solution.

[0042] In the second step, the chlorinated polyolefin resin dispersion is added to the CMC solution prepared in the previous step, and the equipment is used for stirring. The stirring parameters are set as follows: revolution 80r / min, rotation 0, and stirring time is 180min. The glue accounts for 47% of the solid content of the conductive glue.

[0043] In the third step, one or more carbon materials of acetylene black, Ketjen black, Super-P, and graphene are added to the glue prepared in the previous step, and the stirring parameters are set as follows: revolution 30r / min, rotation 200r / min, stirring time 10min, after stirring, scrape off the material adhering to the stirring paddle, adjust the rotation parameter of the equipment to 800~1800r / min, the revolution parameter remains unchanged, the time is 60min, after stirring, add one or two carbon materials of carbon nanotubes (CNTs) or carbon nanofibers (VGCF), and continue stirring for 60min without changing the stirring parameters after adding. The conductive filler accounts for 47% of the solid content of the conductive glue, and the mass of the one-dimensional carbon material accounts for 5% of the conductive filler. After stirring, the appearance of the prepared material is an oily viscous liquid.

[0044] The fourth step is to add the material obtained in the previous step into the colloid mill, and control the number of colloid milling to be 2 to 8 times.

[0045] The fifth step is to use a mixer to stir the material obtained after the previous step, set the stirring speed to 20 rpm, and stir continuously for 20 minutes. After stirring, use an 80-mesh sieve to filter twice.

[0046] Step 6: Seal and store the material prepared in the previous step. The viscosity should be controlled between 2000 and 5000 mPa.s.

[0047] The seventh step is to place the conductive carbon and activated carbon in a blast oven for high-temperature dehydration. The temperature of the oven should be set at 150°C and the baking time should be 12 hours.

[0048] In the eighth step, the activated carbon and conductive carbon materials baked in the previous step are added into the ribbon mixer in a ratio of 85:5, the stirring speed is set to 30 rpm, and the stirring is performed for 12 hours.

[0049] In the ninth step, add the PTFE powder and the carbon powder mixed in the previous step into the ribbon mixer, with the mass of PTFE accounting for 1-9% of the total weight. Set the stirring environment temperature to 0-15°C, the speed to 30 rpm, and stir for 4 hours.

[0050] Step 10: Take out the material mixed in the previous step and place it in a preheated blast oven. Set the oven temperature at 100~180℃. Test the temperature at the center of the material. Continue heating for 1h after reaching the set temperature. Add the baked material to the screw feeder. Control the feeding speed at 10kg / h. Add the mixed material to the airflow mill. Choose a crushing pressure of 0.5~0.8MPa. Choose a material feed pressure of 0.8MPa. The processing environment temperature is 25±5℃. The relative humidity needs to be lower than 30%RH.

[0051] In the eleventh step, the roller press is preheated and the temperature is set to 100~190℃. After the equipment reaches the set temperature and the temperature stabilizes, the roller gap spacing is adjusted to 0.5~1.5mm, the speed ratio of the two rollers is 1:2, and the line pressure is set to 100~400N / mm. The edge defect pole piece of the carbon film after rolling is cut off, and the width of the carbon film after slitting is 220mm. The carbon film after slitting is rolled up, and the winding tension is controlled at 2N.

[0052] In the twelfth step, add the conductive glue prepared in the sixth step into the material tank of the equipment. Before using the conductive glue, it needs to be stirred at a low speed for 10 minutes. The glue head of the equipment transfers the conductive glue to the button shell cover. The thickness of the transferred conductive glue is controlled at 0.01mm, and the area is between 70% and 150% of the electrode area.

[0053] In the thirteenth step, the entire tray of shell covers that have completed the transfer operation in the previous step is transferred to a tunnel furnace for baking. The baking temperature is set at 150°C and the time is controlled at 1 to 20 minutes.

[0054] In the fourteenth step, the whole roll of carbon film rolled in the eleventh step is loaded, and the equipment punches the carbon film into the shell cover prepared in the thirteenth step. During the punching process, the temperature of the shell cover needs to be maintained above 100°C. The punch presses the punched carbon film onto the shell cover. The pressure is set to 2t and the holding time is 1 to 20s. The processed carbon film needs to fit tightly inside the shell cover.

[0055] In the fifteenth step, the shell cover prepared in the previous step is placed in a vacuum oven, the vacuum degree is controlled below -85Kpa, the baking temperature is set to 80~150℃, and the baking time is 4~20h.

[0056] Step 16: Use liquid injection to add electrolyte to the shell cover after dehydration in the previous step. After assembly, the capacitors are sealed and cleaned, aged and sorted.

[0057] Step 17: Connect the assembled single capacitors in series to prepare a 5.5V / 1.0F button-type supercapacitor product, and test the product's voltage retention, high temperature load performance, and voltage retention rate to obtain the following: Figure 3 and Figure 4 data.

[0058] The above example is only a preferred solution of the present invention and does not constitute any limitation to the present invention. There may be other variations within the scope of the technical solution described in the claims. Any improvement, modification and replacement made on the basis of the principle and spirit of the present invention shall be protected by the present invention.

Claims

1. A method for preparing a dry electrode of a button supercapacitor, characterized in that: The following steps are included: 1) Use CMC as thickener, chlorinated polyolefin resin as binder, and carbon material as conductive filler. After mixing, use double planetary mixer to stir, and then use colloid mill to disperse the materials. The mixed conductive filler accounts for 10-60% of the solid content of the conductive glue. After the materials are stirred, use high-speed shearing equipment to process the materials. Use the high shearing line speed of the equipment to make the materials evenly and finely dispersed to obtain conductive glue; 2) Take activated carbon and conductive carbon and mix them thoroughly, the mass of conductive carbon accounts for 1-10% of the mass of the mixture. After stirring, control the stirring environment temperature at 0-15°C. After the temperature is reached, add PTFE powder, the mass of PTFE accounts for 1-9% of the total weight, and then fully heat the materials, and then perform air flow crushing. During the entire processing process, the temperature of the materials is maintained between 70-150°C; Pressing of dry carbon film, the material crushed in step 2 is roller pressed, the temperature of the roller pressing process equipment is 100-190°C, the roller gap is set to 0.5-1.5mm, and the roller pressing pressure is 100-400N / mm to obtain a carbon film; 3) Prepare button capacitor electrodes, transfer the conductive glue prepared in step 1) to the shell cover by transfer printing, control the thickness of the transferred conductive glue to be between 0.005 and 0.02 mm, and the area to be between 70 and 150% of the electrode area, and use a tunnel furnace for baking, the baking temperature is set at 80 to 180°C, and the time is controlled at 1 to 20 min. During the process of punching the carbon film prepared in step 2 onto the shell cover, the temperature of the shell cover needs to be maintained at 80 to 180°C, and the punch presses the punched carbon film onto the shell cover, the pressure is set to 1 to 10t, and the pressure holding time is 1 to 20s. The processed carbon film needs to fit tightly inside the shell cover.

2. The method for preparing a dry electrode of a button supercapacitor according to claim 1, characterized in that: In step 1), the carbon material includes two mixtures, one is one or a pair of acetylene black, Ketjen black, Super-P and graphene, and the other is a one-dimensional carbon material, the one-dimensional carbon material is one or a mixture of carbon nanotubes (CNTs) and carbon nanofibers (VGCF), and the mass of the one-dimensional carbon material accounts for between 1% and 20% of the mass of the carbon material.

3. The method for preparing a dry electrode of a button supercapacitor according to claim 2, characterized in that: In step 1), CMC and chlorinated polyolefin resin are first mixed, and then one or more carbon materials selected from acetylene black, Ketjen black, Super-P and graphene are mixed and stirred. After the material becomes an oily viscous liquid, one-dimensional carbon material is added and stirring is continued.

4. The method for preparing a dry electrode of a button supercapacitor according to claim 3, characterized in that: In step 1), a double planetary mixer is used for stirring, and finally a colloid mill is used to disperse the material, and then a high-speed shearing device is used to process the material, and the high shearing linear speed of the device is used to make the material evenly and finely dispersed.

5. The method for preparing a dry electrode of a button supercapacitor according to claim 2, characterized in that: In step 1), CMC is first fully dissolved in deionized water, and then a chlorinated polyolefin resin dispersion is added, and a uniform solution is prepared after stirring. The conductive filler is added to the solution prepared in the previous step, and high-speed stirring and dispersion are performed, and then a high-speed shear mixer is used for processing. The filtered material is then stirred at a low speed and then filtered using a filter. The filtered material is sealed and stored and taken out when used.

6. The method for preparing a dry electrode of a button supercapacitor according to claim 1, characterized in that: Step 2) Place the conductive carbon and activated carbon in different ovens for high-temperature dehydration. The oven temperature should be set at 100-180°C and the baking time should be 6-12 hours. The timing starts when the center temperature of the material reaches the set value. Weigh the activated carbon and conductive carbon after dehydration according to the proportion and then stir.

7. The method for preparing a dry electrode of a button supercapacitor according to claim 1, characterized in that: In step 3), add the conductive glue into the material tank of the equipment, and then stir the conductive glue at a low speed, with the stirring speed controlled below 40 rpm, for 2 to 30 minutes, and then transfer the conductive glue to the button shell cover.

8. The method for preparing a dry electrode of a button supercapacitor according to claim 1, characterized in that: In step 2), the speed ratio of the two rollers of the roller press is 1:2, and the edge defective pole piece of the carbon film after rolling is cut off. The width of the carbon film after slitting is 220 mm. The carbon film after slitting is rolled up, and the winding tension is controlled at 1~8N.

9. The method for preparing a dry electrode of a button supercapacitor according to claim 1, characterized in that: In step 2), after adding PTFE powder, place it in a preheated blast oven with the oven temperature set at 70~150℃. Test the temperature at the center of the material and continue heating for 0.5~4h after reaching the set temperature. Add the baked material to the screw feeder with a feeding speed of 4~10kg / h. Use a jet mill to process the material with a crushing pressure of 0.5~0.8MPa and a feeding pressure of 0.6~0.8MPa. The processing environment temperature is 25±5℃ and the relative humidity needs to be lower than 30%RH.

10. The method for preparing a dry electrode of a button supercapacitor according to claim 1, characterized in that: Step 3) The prepared shell cover and diaphragm are placed in a vacuum oven, the vacuum degree is controlled below -85 KPa, the baking temperature is set to 80-150°C, and the baking time is 4-20 hours to obtain the required electrode.

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