CN109449000B - Novel super capacitor - Google Patents

Abstract

The invention relates to a super capacitor, comprising an electrode sheet and a diaphragm, the electrode sheet includes a plug-in pole segment extending into the capacitor, one end of the plug-in pole segment is provided with a fixed pole segment, and one end of the fixed pole segment is provided with a The locking pole segment, one end of the locking pole segment is provided with an external connecting pole segment, the plug-in pole segment and the fixed pole segment are integrally formed in the shape of an "L"-shaped folded plate, and the locking pole segment as a whole is "L" shaped. U"-shaped, the above-mentioned plug-in pole segments are inserted into the capacitor. The iron oxide produced by the reaction on the electrode sheet is evenly distributed among the graphene oxide, which effectively avoids the agglomeration of the graphene oxide. Through the action of an external magnetic field, the iron oxide is always in a paramagnetic vertical state to form tiny iron needles, which help the graphene oxide coating to form a needle-like microstructure surface. This structure has super-oleophilic properties, which can be in contact with the electrolyte surface of the organic phase more closely than the general structure, so that the specific surface area provided by the material can be fully utilized.

Description

A new type of supercapacitor

technical field

The invention relates to the technical field of capacitors, in particular to a novel super capacitor.

Background technique

Supercapacitors are a new type of green energy storage devices that can be rapidly charged/discharged. It has the dual functions of traditional electrolytic capacitors and batteries, and its power density is much higher than that of batteries, and its charge and discharge speed is much faster than that of batteries; its energy density is much higher than that of traditional electrolytic capacitors. Compared with traditional electrolytic capacitors and batteries, supercapacitors have the advantages of small size, high energy density, fast charge and discharge speed, long cycle life, high discharge power, wide operating temperature range of -40℃～85℃, good reliability and low cost, etc. advantage. Therefore, supercapacitors are becoming a new, efficient, practical, green and environmentally friendly fast charge-discharge energy storage device. It has a wide range of application prospects in energy, automobile, medical and health, electronics, military and other fields.

In the production and use of current capacitors, the electrode pads need to be installed on the capacitor. However, the existing electrode pads are not easy to be positioned on the housing during installation, and it is especially easy to cause the electrode pads to move when the epoxy resin is encapsulated. affect product quality. At the same time, traditional capacitors generally use silver electrodes. During the operation of the capacitor, the silver in the silver electrode will continuously migrate to the inside of the capacitor, thereby shortening the distance between the two silver electrodes, resulting in a decrease in the high voltage breakdown capability of the capacitor.

Electrical devices have higher and higher requirements on the power performance of supercapacitors, requiring long-term high-current charging and discharging of supercapacitors, which will generate more heat inside the supercapacitor. Since the supercapacitor is composed of a shell, an electrolyte, a coiled core formed by winding positive and negative pole pieces and a diaphragm, the internal structure is compact and the remaining space is small. If the heat generated is not dissipated in time or the heat is unevenly distributed in the supercapacitor, It will reduce the service life of supercapacitors, especially the old fire and damage caused by local overheating caused by uneven distribution, which often have a greater negative impact on capacitors.

At the same time, graphene oxide (Graphene oxide) is a two-dimensional crystalline ultra-thin material composed of sp ² hybridized carbon atoms connected to each other. A single layer of graphene oxide is only one carbon atom thick, and the carbon atoms are all They are connected to each other in the form of covalent bonds, and the whole presents a hexagonal annular honeycomb shape, which is a two-dimensional plane material in the strict sense. Graphene oxide has a large specific surface area and excellent electrical conductivity, which makes it easier to form an electric double layer, and has excellent chemical and thermal stability at the same time. Due to the large surface and extremely thin thickness of graphene oxide, it is easy to form three-dimensional wrinkles and superimposed spatial structures, so that nano-scale channels and holes can be formed, which is conducive to the diffusion of electrolyte inside the material. In addition, graphene oxide also has excellent mechanical flexibility, so graphene oxide is a very ideal supercapacitor electrode material.

However, graphene oxide is very easy to agglomerate during use, which greatly reduces the specific surface area of the material, thereby affecting the capacitance. In the prior art, although some materials such as polyaniline are added to improve the dispersibility of graphene oxide to solve the problem of its agglomeration, there are also difficulties such as complicated operation and difficulty in practical promotion. Moreover, even if the agglomeration problem is solved, surface modification of graphene oxide to obtain a larger specific surface area has very important practical significance for its further application.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies in the prior art and provide an improved super capacitor.

For achieving the above object, the technical scheme adopted in the present invention is:

A super capacitor, comprising an electrode sheet and a diaphragm, characterized in that: the electrode sheet comprises a plug-in pole segment extending into the capacitor, and the electrode sheet is processed with graphene on at least one surface of the plug-in pole segment; the The specific processing steps of graphene are:

(1) by weight, add 0.2-0.5 parts of graphene oxide to 1000 parts of deionized water, ultrasonically disperse graphene oxide; then add 20-45 parts of urea and 1.5-3.75 parts of FeCl ₃ ·6H ₂ O, ultrasonically mix Homogenize, heat in a water bath at 85 to 95 °C for 2 to 3 hours, and then cool to room temperature; then add 0.1 to 0.5 parts of phenylhydrazine, mix well, and react at 200 °C for 5 to 7 hours to obtain reduced graphene oxide/α-crystalline iron oxide composite material;

(2) using the electrophoretic deposition method to make the reduced graphene oxide/α crystal iron oxide composite material form a film on the surface of the object to be coated, during the film forming process, the object to be coated is always in a uniform external magnetic field; the magnetic field strength is 0.5 T, the magnetic field spacing is 10-30mm; the coating time is 10-60min, that is, the object that has been plated with reduced graphene oxide/iron oxide coating;

(3) Place the object plated with reduced graphene oxide/iron oxide coating in an argon atmosphere, keep at 800-850°C for 2-3 hours, then ultrasonically clean the electrode surface coating with deionized water for 10-30 minutes, and dry Then a needle-shaped reduced graphene oxide coating structure is formed;

One end of the plug-in pole segment is provided with a fixed pole segment, one end of the fixed pole segment is provided with a locking pole segment, and one end of the locking pole segment is provided with an outer connecting pole segment, and the plug-in pole segment and the The entire fixed pole segment is in the shape of an "L"-shaped folded plate, and the entire locking pole segment is in the "U" shape.

Preferably, one side of the plug-in pole segment is provided with a first slot, the bottom of the first slot is provided with a first bump, and the first bump is along the length of the slot of the first slot. A plurality of directions are arranged at intervals, and the cross section of the first convex point is a right-angled trapezoid.

Preferably, a threaded hole is provided on the fixed pole segment, and a gasket is provided at the lower end of the threaded hole.

Preferably, the bottom plate surface of the locking pole segment is provided with second bumps, the second bumps are arranged at intervals along the length direction of the bottom plate, and the cross-section of the second bumps is triangular; The two sides of the outer connecting pole segment are respectively provided with second card slots.

Preferably, the arc transition between one end of the plug-in pole segment and the fixed pole segment, the arc transition between the fixed pole segment and the locking pole segment, and the transition between the locking pole segment and the outer connecting pole segment Arc transition.

Preferably, in the step (1), according to the mass ratio, the graphene oxide: FeCl ₃ ·6H ₂ O=2:15; the magnetic field spacing in the step (2) is 20 mm, and the coating time in the step (2) is 30min.

Preferably, in step (1), the graphene oxide is 0.3 parts, the urea is 30 parts, the FeCl ₃ ·6H ₂ O is 2.25 parts, and the phenylhydrazine is 0.3 parts.

Preferably, the magnetic field spacing in step (2) is 20 mm, and the coating time in step (2) is 30 minutes.

Preferably, the diaphragm includes a diaphragm base layer, first and second heat dissipation layers are respectively provided on both sides of the diaphragm base layer, the first and second heat dissipation layers are respectively attached and then fixed on the diaphragm base layer, and the first and second heat dissipation layers are respectively attached to the diaphragm base layer. 1. The second heat dissipation layers may not be connected to each other; the processing methods of the first and second heat dissipation layers are:

According to the volume fraction of the solution, the coating is composed of 13-30% of silica sol, 13-30% of graphene oxide dispersion, 40-75% of polystyrene emulsion, and the total percentage is 100%, and The silica sol and the graphene oxide dispersion are of equal volume; then the diaphragm base layer is immersed in the coating, taken out after 8 to 10 minutes, and the take-out time is less than or equal to 10s, and dried at room temperature; repeat the above-mentioned diaphragm base layer dipping to dry Step 3 times, heat treatment at 300°C after drying to obtain a thermally conductive coating;

in,

The preparation method of the silica sol is as follows: adding hexyl orthosilicate into anhydrous ethanol, stirring evenly, adding concentrated ammonia water, stirring at 45° C. for 12 hours, and then adding vinyltriethoxysilane to obtain dioxide dioxide Silica sol; wherein, by volume, hexyl orthosilicate: absolute ethanol: concentrated ammonia: A-151=10:50～120:2～5:1;

The preparation method of the graphene oxide dispersion liquid is as follows: adding 1 part of graphene oxide to 20-30 parts of deionized water by weight, and ultrasonically treating it with a power of 60W for 3 hours to obtain a graphene oxide dispersion liquid;

The preparation method of the polystyrene emulsion is as follows: adding styrene monomer into deionized water, then adding sorbitan monooleate polyoxyethylene ether, fully stirring to form an emulsion, and feeding the obtained emulsion with nitrogen at 70° C. , and then add an aqueous solution of ammonium persulfate with a volume concentration of 3%, and polymerize for 7 hours to obtain a polystyrene emulsion; wherein, in parts by weight, styrene monomer: deionized water: sorbitan monooleate polyoxygen Vinyl ether: ammonium persulfate aqueous solution=1:3-7:0.05-0.10:0.1-0.3.

Preferably, the coating is composed of 22% of silica sol, 56% of graphene oxide dispersion and 22% of polystyrene emulsion according to the volume fraction of the solution; the take-out speed is 10cm/min.

Compared with the prior art, the technical effect of the present invention is: the above-mentioned plug-in pole segment is inserted into the capacitor, thereby realizing the preliminary fixing of the electrode piece and the capacitor, and the above-mentioned locking pole segment is clamped on the cover of the capacitor. between the electrode and the casing, so as to further fix the electrode sheet, avoid the movement of the electrode sheet, and fix the fixed pole segment on the cover of the electrode sheet with bolts, so that the electrode sheet can be effectively positioned on the casing to avoid When the epoxy resin is potted, the position of the electrode pads is moved to ensure product quality.

In addition, the iron oxide produced by the reaction on the electrode sheet of the present invention is evenly distributed among the graphene oxides, which effectively avoids the agglomeration of the graphene oxides. Through the action of an external magnetic field, the iron oxide is always in a paramagnetic vertical state to form tiny iron needles, which help the graphene oxide coating to form a needle-like microstructure surface. This structure is a biomimetic lotus leaf surface structure with super-lipophilic properties, which can be more closely contacted with the electrolyte surface of the organic phase than the general structure, so that the specific surface area provided by the material can be fully utilized. Compared with the prior art, the heat dissipation performance and electrical conductivity of the electrode sheet are greatly improved. At the same time, the microstructure is uniformly distributed and has a large specific surface area, which is about 5-6 times the specific surface area of the irregular spherical pores formed by general etching. The present invention also determines the specific ratio of graphene oxide and FeCl ₃ ·6H ₂ O (2:15 by mass ratio), higher than this value, the amount of graphene oxide is too large, graphene oxide is easy to agglomerate, and the coating The increase rate of the specific surface area is not ideal; below this value, the FeCl ₃ ·6H ₂ O dosage is too large, and the FeCl ₃ ·6H ₂ O is prone to agglomeration.

The first and second heat dissipation layers on the diaphragm can effectively achieve more uniform distribution of the heat generated in the capacitor and rapid dissipation through the connection position of the diaphragm, thereby avoiding overheating inside the capacitor and improving the service life of the super capacitor.

Description of drawings

Fig. 1 is a structural schematic diagram of a supercapacitor pole piece;

Fig. 2 is the partial structure schematic diagram of supercapacitor;

Fig. 3 is a schematic diagram of graphene/iron oxide coating formation;

Fig. 4 is a schematic diagram of graphene coating formation;

FIG. 5 is a schematic view of the structure before and after the thermal conductive coating of the present invention is formed.

Detailed ways

1 and 2, the super capacitor will be described in further detail: a super capacitor pole piece, including a plug-in pole segment 10 extending into the capacitor, and one end of the plug-in pole segment 10 is provided with a fixed pole segment 20. One end of the fixed pole segment 20 is provided with a locking pole segment 30, one end of the locking pole segment 30 is provided with an outer connecting pole segment 40, and the plugged pole segment 10 and the fixed pole segment 20 are integrally formed in the same manner. "L"-shaped folded plate, the locking pole segment 30 is in the shape of "U" as a whole;

The above-mentioned plug-in pole segment 10 is inserted into the capacitor A, so as to realize the preliminary fixing of the electrode piece and the capacitor A, and the above-mentioned locking pole segment 30 is clamped between the cover body B and the casing A of the capacitor, thereby realizing the The further fixing of the electrode sheet avoids the movement of the electrode sheet, and the fixed pole segment 20 is fixed on the cover body B of the electrode sheet by means of bolts C, so that the electrode sheet can be effectively positioned on the casing, avoiding the need for potting epoxy resin. Cause the position of the electrode pad to move to ensure the quality of the product.

In order to further facilitate the assembly and connection, one side of the plug-in pole segment 10 is provided with a first slot 11 , and the bottom of the first slot 11 is provided with a first bump 12 . A plurality of slots are arranged at intervals along the slot length direction of the first card slot 11 , the cross section of the first bump 12 is a right-angled trapezoid, and the oblique side of the right-angled trapezoid is arranged upward. On the one hand, the heat dissipation area is increased, and at the same time, when the diaphragm is wound, it can prevent downward slippage, which facilitates the accurate positioning of the diaphragm and the electrode sheet.

The above-mentioned first slot 11 is embedded in the casing A of the capacitor, and the connection reliability of the electrode sheet can be further ensured by using the first bump 12 . Specifically, the fixed pole segment 20 is provided with a threaded hole 21 , and the lower end of the threaded hole 21 is provided with a gasket 22 .

More preferably, in order to further improve the connection reliability, the bottom plate surface of the locking pole segment 30 is provided with second bumps 31, and a plurality of second bumps 31 are arranged at intervals along the length direction of the bottom plate surface. , the cross section of the second bump 31 is triangular.

Two sides of the outer connecting pole segment 40 are respectively provided with second card slots 41 ; nickel and tin can be coated on the second card slots 41 to ensure the conduction performance of the electrical connection.

In order to ensure the strength of the electrode sheet and reduce the possibility of breakage, there is an arc transition between one end of the plug-in pole segment 10 and the fixed pole segment 20, and an arc transition between the fixed pole segment 20 and the locking pole segment 30. , the arc transition between the locking pole segment 30 and the outer connecting pole segment 40 .

The specific preparation method for processing the graphene oxide coating on the electrode sheet plugged into the pole segment 10 of the present invention is as follows:

1. Preparation of reduced graphene oxide/α-crystalline iron oxide composite material: by weight, add 0.2 to 0.5 parts of graphene oxide to 1000 parts of deionized water, and ultrasonically mix (10min, 60W) to disperse the graphite oxide Add 20-45 parts of urea and 1.5-3.75 parts of FeCl ₃ ·6H ₂ O, mix well, and sonicate for 10 min. Heating and stirring in a water bath at 90°C for 3h, and then cooling to room temperature; then adding 0.1-0.5 parts of phenylhydrazine, mixing and adding to the reaction kettle, and reacting at 200°C for 6h to obtain reduced graphene oxide/α-crystalline iron oxide composite material (aqueous solution). ).

2. Forming the graphene oxide/iron oxide coating: using the electrophoretic deposition method, the reduced graphene oxide/α-crystalline iron oxide composite material is formed into a film on the surface of the electrode to be coated. The electrophoretic deposition method specifically includes: ultrasonically mixing the prepared reduced graphene oxide/α-crystalline iron oxide composite material (aqueous solution) again for 10 minutes, using a JY 600 electrophoresis apparatus as a DC power supply, and applying 80V cm ^-1 between the electrodes The constant electric field, electrophoretic deposition for 30s, after the deposition is completed, quickly take out the coated electrode, and dry it at 90 °C.

During the entire film forming process, the electrode to be coated is always in a uniform external magnetic field; the magnetic field strength is 0.5T, the magnetic field spacing is 10-30mm; the coating time is 10-60min, and the coated electrode is obtained. The specific structure is shown in Figure 3.

3. Forming a graphene oxide coating: place the coated electrode material in an argon atmosphere, raise the temperature to 800-850 °C, and keep the temperature for 2 hours, then ultrasonically clean the electrode surface coating with deionized water for 10 minutes to remove iron Elemental, after drying, a needle-shaped graphene oxide film is formed, and the specific structure is shown in Figure 4.

The present invention will be further explained below in conjunction with specific embodiments.

Comparative Example 1

According to the above operation steps 1 and 2, without adding urea and FeCl ₃ ·6H ₂ O, without performing step 3, the remaining steps are exactly the same, and the graphene oxide coating comparative example 1 is prepared. Wherein, in parts by weight, graphene oxide is 0.3 parts, phenylhydrazine is 0.3 parts, the magnetic field spacing is 20 mm, and the coating time is 30 minutes.

Comparative Example 2

1. In parts by weight, add 0.3 part of graphene oxide to 1000 parts of deionized water, and ultrasonically disperse the graphene oxide for 10 minutes to obtain a graphene oxide dispersion.

2. Electrophoretic deposition method, the graphene oxide dispersion is coated on the surface of the electrode.

3. Evenly coat the coated side of the coated electrode with a layer of nano-iron oxide with a coating thickness of about 50 nm, react at 800°C for 30 minutes, ultrasonically clean the surface with deionized water for 10 minutes, remove the iron element, and obtain the oxide prepared by the ordinary etching method. Graphene coating comparative example 2.

Example

1. Using the method of the present invention, 23 groups of graphene oxide were prepared. The specific preparation parameters of each group are shown in Table 1, wherein the unit of each material is parts by weight.

The specific preparation parameters of each embodiment of table 1

2. Specific surface area test.

BET specific surface area test at liquid nitrogen temperature: American Micromeritics ASAP 2010 specific surface area and pore analyzer. The results are shown in Table 2.

Table 2 Specific surface area of each embodiment and comparative example

Example Specific surface area (m²/g) Example 1 986.1 Example 2 1205.3 Example 3 1468.5 Example 4 875.2 Example 5 1189.2 Example 6 852.4 Example 7 1348.2 Example 8 960.5 Example 9 932.5 Example 10 902.7 Example 11 1432.7 Example 12 1442.9 Example 13 1448.6 Example 14 1440.2 Example 15 1456.2 Example 16 1465.4 Example 17 1466.3 Example 18 1329.1 Example 19 1318.2 Example 20 901.2 Example 21 1104.5 Example 22 1465.9 Example 23 1458.2 Comparative Example 1 645.2 Comparative Example 2 962.5

It can be seen from the above table and simple calculation that, according to the mass ratio, when graphene oxide: FeCl ₃ ·6H ₂ O=2:15, the effect is the best. The amount of graphene oxide is too large, the dispersion of graphene oxide, and the specific surface area of the coating are not ideal; if the amount of FeCl ₃ ·6H ₂ O is too large, FeCl ₃ ·6H ₂ O is prone to agglomeration, and the specific surface area of the coating is not ideal.

3. Pore size distribution test.

Using Micromeritics ASAP 2010 specific surface area and porosity analyzer in the United States, the surface pore size distribution ratio of the coatings of each example and the comparative example was tested, and according to the test results, the proportion distribution of pores of each size was calculated. The results are shown in Table 3.

Table 3 Pore size distribution of each example and comparative example

It can be seen from the above table that the pore size of the coating prepared by using the technical solution of the present invention is mainly concentrated in 25-45 nm, followed by 45-65 nm; while the pore size of Comparative Example 2 is different, and it is distributed in each size. . Since the comparative example 1 did not perform etching and other treatments, the pore size distribution was not measured.

4. Specific capacitance test.

The electrolyte was selected as a KOH solution with a mass fraction of 30%, and a copper sheet was used as the coating electrode of each group of examples and comparative examples. Temperature 25°C.

Specific capacitance C(F/g)=lΔt/ΔV; among them, l is the discharge current density (mA/g), Δt is the discharge time (s), and ΔV is the voltage change (V) during the discharge process.

The results are shown in Table 4.

Table 4 Specific capacitance effect of each embodiment and comparative example

It can be seen from the above table that the specific capacitance of each embodiment has been significantly improved compared with the comparative example, indicating that the technical solution and the needle-like structure of the present invention can indeed effectively increase the relevant performance of the capacitor. In addition, the retention rate of 2000 times of charge and discharge proves that the material prepared by the present invention has an excellent service life and can be actually put into production and use.

The supercapacitor of the present invention is composed of a casing, an electrolyte solution, positive and negative electrode sheets and a diaphragm wound. Therefore, the present invention also improves the diaphragm, another core component of the capacitor. The improved supercapacitor diaphragm includes a diaphragm base layer, and the thickness of the above-mentioned diaphragm base layer is about 0.5 μm; it can be purchased specially; the two sides of the diaphragm base layer are respectively provided with a first and a second heat dissipation layer, and the first and second heat dissipation layers are respectively provided. The heat dissipation layers are respectively attached and then consolidated on the diaphragm base layer, and the first and second heat dissipation layers are not connected or in contact with each other; the processing methods of the first and second heat dissipation layers are:

Mix silica sol, graphene oxide dispersion and polystyrene emulsion to form a coating colloid, immerse the carrier to be dissipated (such as a radiator) into the coating colloid solution, take it out after 8-10 minutes, and take out time ≤ 10s to ensure The uniformity of the coating on the carrier is dried at room temperature; the above operation is repeated 3 times, and after drying, heat treatment is performed at 300 ° C to obtain a hybrid honeycomb thermally conductive coating with hydrophilic and hydrophobic properties; Silica sol: polystyrene emulsion: graphene oxide dispersion = 13-30%: 40-75%: 13-30%; and the volume of silica sol and graphene oxide dispersion is equal.

in,

Preparation of silica sol: add hexyl orthosilicate to absolute ethanol, stir evenly, then add concentrated ammonia water, stir at 45°C for 12 hours, and then add vinyltriethoxysilane (A-151) to obtain a Silica sol with hydrophobic properties; wherein, in parts by volume, hexyl orthosilicate: absolute ethanol: concentrated ammonia water: A-151=10:50-120:2-5:1.

Preparation of graphene oxide dispersion: adding graphene oxide prepared by Hummers method to deionized water, ultrasonically treating for 3h (power 60W) to obtain graphene oxide dispersion; wherein, by weight, graphene oxide: deionized Water=1:20～30.

Preparation of polystyrene emulsion: adding styrene monomer into deionized water, then adding sorbitan monooleate polyoxyethylene ether (Tween 80), fully stirring to form an emulsion, and the obtained emulsion was fed with nitrogen at 70°C, Then add ammonium persulfate aqueous solution with a concentration of 3%, and polymerize for 7 hours to obtain a polystyrene emulsion; wherein, in parts by weight, styrene monomer: deionized water: Tween 80: ammonium persulfate aqueous solution=1:3～ 7: 0.05 to 0.10: 0.1 to 0.3.

As shown in Figure 5, the left picture of Figure 5 shows: polystyrene forms bubbles, helping silica and graphene oxide to form a honeycomb structure; the right picture of Figure 2 shows: after heat treatment at 300 ℃, polystyrene decomposes, Leave the honeycomb coating structure to prepare for the subsequent heat conduction and heat dissipation of the carrier.

The present invention will be further explained below in conjunction with specific embodiments. In addition, the thermal conductive paint/coating is prepared by using the graphene oxide dispersion prepared by the technical solution within the above range, and the final thermal conductivity is equivalent, so the parameters for preparing the graphene oxide dispersion are not shown in the examples. For the convenience of operation in the following examples, graphene oxide: deionized water=1:25 is used.

Comparative ratio

According to the above method, a graphene oxide dispersion liquid was prepared, and graphene oxide: deionized water=1:25. To prepare a polystyrene emulsion, styrene monomer: deionized water: Tween 80: aqueous ammonium persulfate = 1:5:0.07:0.25. Without adding silica sol, graphene oxide dispersion: polystyrene emulsion = 44%: 56%. The pulling speed was 10 cm/min, and a coating was prepared as a comparative example.

Embodiment 2: the preparation parameter of preferred silica sol

1. According to the above method, 10 groups of silica sols were prepared, and the specific parameters are shown in the table. Graphene oxide dispersion was prepared, graphene oxide: deionized water = 1:25. To prepare a polystyrene emulsion, styrene monomer: deionized water: Tween 80: aqueous ammonium persulfate = 1:5:0.07:0.25. Silica sol: polystyrene emulsion: graphene oxide dispersion = 22%: 56%: 22%. The pulling speed was 10 cm/min, and 10 sets of coatings were prepared.

Table 5 Silica sol specific parameters

group anhydrous ethanol Concentrated ammonia Group 1 50 3 group 2 70 3 group 3 90 3 Group 4 100 3 Group 5 110 3 Group 6 120 3 Group 7 100 2 Group 8 100 4 Group 9 100 5 group 10 100 3

2. Thermal conductivity test: C-THERM TCI thermal conductivity measuring instrument was used to test the thermal conductivity of the above 10 groups of coatings at a test temperature of 20 °C. The results are shown in Table 6.

Table 6 Thermal conductivity display

group Thermal conductivity (W/(m*K)) Group 1 25.6 group 2 25.7 group 3 25.6 Group 4 25.8 Group 5 25.7 Group 6 25.7 Group 7 25.6 Group 8 25.7 Group 9 25.7 group 10 25.7 Comparative ratio 39.8

3. Test of heating and cooling speed of heating and cooling cycle: put 50% ethylene glycol and 50% water (volume ratio) into the inside of the radiator. Apply a pressure of 100kPa±20kPa, perform a temperature cycle from 10°C to 90°C, and record the time required for the heating process of each coating material from 10°C to 90°C and the time required for the cooling process from 90°C to 10°C. The results are shown in Table 7.

Table 7 Display of heating and cooling effect of cooling and heating cycle

group Heating time (min) Cooling time (min) Group 1 15.6 5.4 group 2 15.4 5.3 group 3 15.3 5.8 Group 4 15.7 5.3 Group 5 16.1 5.5 Group 6 16.2 5.5 Group 7 15.8 5.7 Group 8 15.9 5.6 Group 9 15.8 5.4 group 10 15.7 5.3 Comparative ratio 6.5 18.9

It can be seen from the above Tables 6 and 7 that the silica sol prepared within the scope of the present invention has little effect on the performance of the final thermally conductive coating, and the effect is comparable.

Using pure graphene oxide, the thermal conductivity is very high, but in the temperature rise and fall test, the heating time of the pure graphene oxide coating with higher thermal conductivity is significantly lower than that of each group of the present invention, and the cooling time is significantly higher than that of each group of the present invention, It shows that its thermal conductivity is obviously weaker than that of the composite coating material prepared by the present invention.

Embodiment 3: the preparation parameter of preferred polystyrene emulsion

1. Prepare 8 groups of polystyrene emulsions according to the above method, and the specific parameters are shown in Table 8. 8 groups of silica sols were prepared according to the method of Example 2, Group 4; graphene oxide dispersion was prepared, graphene oxide: deionized water=1:25. According to silica sol: polystyrene emulsion: graphene oxide dispersion = 22%: 56%: 22%, and a pulling speed of 10 cm/min, 8 groups of coatings were prepared.

Table 8 Specific parameters of each group

group Deionized water Tween 80 Aqueous solution of ammonium persulfate Group 1 3 0.07 0.25 group 2 5 0.07 0.25 group 3 7 0.07 0.25 Group 4 5 0.05 0.25 Group 5 5 0.10 0.25 Group 6 5 0.07 0.10 Group 7 5 0.07 0.20 Group 8 5 0.07 0.30

2. The thermal conductivity was tested according to the method of Example 2, and the results are shown in Table 9.

Table 9 Thermal conductivity display

group Thermal conductivity (W/(m*K)) Group 1 26.0 group 2 26.1 group 3 25.9 Group 4 26.0 Group 5 26.1 Group 6 25.8 Group 7 25.7 Group 8 25.8

3. The heating and cooling effect was tested according to the method of Example 2, and the results are shown in Table 10.

Table 10 Display of heating and cooling effect of cold and hot cycle

It can be seen from the above-mentioned Table 9 and Table 10 that the use of the polystyrene emulsion prepared within the scope of the present invention has little effect on the performance of the final thermal conductive coating, and the effect is comparable. The relevant data of the comparative example has been shown in the second embodiment, and the effect here is equivalent, so it is not shown again.

Embodiment 4: the preparation parameter of optimal thermal conductivity coating

1. Prepare 5 groups of silica sols according to the method of Example 2, Group 4; Prepare 5 groups of polystyrene emulsions according to the method of Example 3, Group 2; According to graphene oxide dispersion, graphene oxide: deionized water=1 : 25, and 5 groups of graphene oxide dispersions were prepared. Five groups of coatings were prepared according to the above method, and the specific parameters for preparing the coatings are shown in Table 11.

Table 11 Specific parameters of each group

2. The thermal conductivity was tested according to the method of Example 2, and the results are shown in Table 12.

Table 12 Thermal conductivity display

group Thermal conductivity (W/(m*K)) Group 1 16.5 group 2 23.2 group 3 26.1 Group 4 28.9 Group 5 30.1 Group 6 25.1 Group 7 23.2 Comparative ratio 39.8

3. The temperature rise and fall effect was tested according to the method of Example 2, and the results are shown in Table 13.

Table 13 Display of heating and cooling effect of cooling and heating cycle

group Heating time (min) Cooling time (min) Group 1 12.3 7.6 group 2 14.2 6.5 group 3 15.8 5.3 Group 4 13.3 6.2 Group 5 12.9 7.9 Group 6 13.1 7.2 Group 7 13.5 7.8 Comparative ratio 6.5 18.9

It can be seen from Table 12 and Table 13 that with the increase of the amount of graphene oxide, the thermal conductivity increases continuously, but this is not completely the case when the temperature rises and falls. If the amount of graphene oxide and silica is too low, the honeycomb structure cannot be effectively formed, the temperature rises faster, and the temperature becomes slower; if the amount of graphene oxide is too high, the temperature rise and fall effect is not satisfactory.

Furthermore, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and range of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (9)

1. The utility model provides a super capacitor, includes electrode slice and diaphragm, its characterized in that: the electrode plate comprises an insertion electrode segment (10) extending into the capacitor, and graphene is processed on at least one surface of the insertion electrode segment (10); the specific processing steps of the graphene are as follows:

(1) adding 0.2-0.5 part of graphene oxide into 1000 parts of deionized water according to parts by weight, and ultrasonically dispersing the graphene oxide; then adding 20-45 parts of urea and 1.5-3.75 parts of FeCl₃·6H₂O, ultrasonically mixing, heating in water bath at 85-95 ℃, stirring for 2-3 h, and then cooling to room temperature; then adding 0.1-0.5 part of phenylhydrazine, uniformly mixing, and reacting for 5-7 h at 200 ℃ to obtain a reduced graphene oxide/alpha crystal form ferric oxide composite material;

(2) forming a film on the surface of an object to be coated by using the reduced graphene oxide/alpha crystal form iron oxide composite material by using an electrophoretic deposition method, wherein the object to be coated is always in a uniform external magnetic field in the film forming process; the magnetic field intensity is 0.5T, and the magnetic field interval is 10-30 mm; coating for 10-60 min to obtain the object coated with the reduced graphene oxide/iron oxide coating;

(3) placing the object plated with the reduced graphene oxide/iron oxide coating in an argon environment, preserving heat for 2-3 h at 800-850 ℃, then ultrasonically cleaning the surface coating of the electrode for 10-30 min by using deionized water, and drying to form a needle-shaped reduced graphene oxide coating structure;

the improved electrode structure is characterized in that a fixed electrode segment (20) is arranged at one end of the insertion electrode segment (10), a locking electrode segment (30) is arranged at one end of the fixed electrode segment (20), an outer connection electrode segment (40) is arranged at one end of the locking electrode segment (30), the insertion electrode segment (10) and the fixed electrode segment (20) are integrally formed into an L-shaped folded plate shape, and the locking electrode segment (30) is integrally U-shaped.

2. The supercapacitor according to claim 1, wherein: one side of grafting utmost point fragment (10) is provided with first draw-in groove (11), the tank bottom of first draw-in groove (11) is provided with first bump (12), first bump (12) set up a plurality ofly along the groove length direction interval of first draw-in groove (11), the cross-section of first bump (12) is right trapezoid.

3. The supercapacitor according to claim 1, wherein: the fixed pole segment (20) is provided with a threaded hole (21), and a gasket (22) is arranged at an orifice at the lower end of the threaded hole (21).

4. The supercapacitor according to claim 1, wherein: second salient points (31) are arranged on the bottom plate surface of the locking pole segment (30), a plurality of second salient points (31) are arranged at intervals along the length direction of the bottom plate surface, and the cross sections of the second salient points (31) are triangular; and second clamping grooves (41) are respectively arranged on two sides of the external connection pole segment (40).

5. The supercapacitor according to claim 1, wherein: the arc transition between one end of grafting utmost point section (10) and fixed utmost point section (20), the arc transition between fixed utmost point section (20) and locking utmost point section (30), the arc transition between locking utmost point section (30) and outer connection utmost point section (40).

6. The supercapacitor according to claim 1, wherein: in the step (1), the graphene oxide is prepared by the following steps: FeCl₃·6H₂O is 2: 15; the distance between the magnetic fields in the step (2) is 20mm, and the coating time in the step (2) is 30 min.

7. The supercapacitor according to claim 6, wherein: in the step (1), the graphene oxide is 0.3 part, the urea is 30 parts, and the FeCl is₃·6H₂2.25 parts of O and 0.3 part of phenylhydrazine.

8. The supercapacitor according to any one of claims 1 to 7, wherein: the diaphragm comprises a diaphragm base layer, a first heat dissipation layer and a second heat dissipation layer are respectively arranged on two sides of the diaphragm base layer, the first heat dissipation layer and the second heat dissipation layer are respectively attached and then fixedly connected to the diaphragm base layer, and the first heat dissipation layer and the second heat dissipation layer are mutually connected or not connected; the processing method of the first and second heat dissipation layers comprises the following steps:

according to the volume parts of the solution, the coating consists of 13-30% of silica sol, 13-30% of graphene oxide dispersion liquid and 40-75% of polystyrene emulsion, the total percentage content is 100%, and the silica sol and the graphene oxide dispersion liquid have the same volume; then immersing the diaphragm base layer into the coating, taking out after 8-10 min, taking out for no more than 10s, and drying at room temperature; repeating the step from the soaking to the drying of the diaphragm base layer for 3 times, and carrying out heat treatment at 300 ℃ after drying to obtain the heat-conducting coating;

wherein,

the preparation method of the silica sol comprises the following steps: adding hexyl orthosilicate into absolute ethyl alcohol, stirring uniformly, adding concentrated ammonia water, stirring for 12 hours at 45 ℃, and adding vinyl triethoxysilane to obtain silicon dioxide sol; wherein, the weight portion of the hexyl orthosilicate is as follows: anhydrous ethanol: concentrated ammonia water: a-151 ═ 10: 50-120: 2-5: 1;

the preparation method of the graphene oxide dispersion liquid comprises the following steps: adding 1 part of graphene oxide into 20-30 parts of deionized water by weight, and carrying out ultrasonic treatment for 3 hours at the power of 60W to obtain a graphene oxide dispersion liquid;

the preparation method of the polystyrene emulsion comprises the following steps: adding a styrene monomer into deionized water, adding sorbitan monooleate polyoxyethylene ether, fully stirring to form an emulsion, introducing nitrogen into the obtained emulsion at 70 ℃, adding an ammonium persulfate aqueous solution with the volume concentration of 3%, and carrying out polymerization reaction for 7 hours to obtain a polystyrene emulsion; wherein, according to the weight portion, the styrene monomer: deionized water: sorbitan monooleate polyoxyethylene ether: 1: 3-7 of an ammonium persulfate aqueous solution: 0.05-0.10: 0.1 to 0.3.

9. The supercapacitor according to claim 8, wherein: according to the volume parts of the solution, the coating consists of 22% of silica sol, 56% of graphene oxide dispersion liquid and 22% of polystyrene emulsion; the take-out speed was 10 cm/min.

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