WO2020062223A1

WO2020062223A1 - One-stop supercapacitor and preparation method therefor

Info

Publication number: WO2020062223A1
Application number: PCT/CN2018/109055
Authority: WO
Inventors: 黄燕; 胡萌萌
Original assignee: 哈尔滨工业大学（深圳）
Priority date: 2018-09-30
Filing date: 2018-09-30
Publication date: 2020-04-02

Abstract

A preparation method for a one-stop supercapacitor, comprising the following steps: preparing a solution: uniformly mixing phosphoric acid, sodium chloride, and deionized water at a weight ratio of 1:1:5-6 to obtain the solution; preparing an electrolyte: uniformly mixing flour and the solution at a weight ratio of 4:3-3.5 to obtain the electrolyte; preparing an electrode: uniformly mixing the solution, activated carbon, and the flour at a weight ratio of 5:2.5-3:1-1.5 to obtain the electrode; and preparing a supercapacitor: obtaining the supercapacitor by sandwiching the electrolyte between two of the electrodes. The supercapacitor has one-stop multifunctional characteristics such as self-repairing, re-stretching after self-repairing, and biodegradability.

Description

One-stop supercapacitor and preparation method thereof

Technical field

The invention relates to the technical field of capacitors, and in particular, to a one-stop supercapacitor and a preparation method thereof.

Background technique

Portable and wearable electronics such as smart skins, computer / processor interfaces, and stretchable circuits are becoming part of our daily lives. Supercapacitors are particularly important as the basic unit of energy supply for these devices. Existing ultracapacitors will inevitably be cut accidentally or be subject to other mechanical deformation and damage during actual application. More importantly, such damage will make the ultracapacitors that can be stretched no longer be damaged. Stretching eventually leads to a sudden reduction in the performance of supercapacitors, or even to discard them, and discarded capacitors cannot be degraded, which places a heavy burden on the environment.

Summary of the Invention

In order to solve the above problems, the present invention provides a one-stop supercapacitor and a preparation method thereof. The supercapacitor also has one-stop multifunctional characteristics such as self-healing, self-healing and re-stretching and biodegradability .

In one aspect, the present invention provides a method for preparing a one-stop supercapacitor, including the following steps: preparing a solution: mixing phosphoric acid, sodium chloride, and deionized water in a weight ratio of 1: 1: 5 to 6 to obtain a uniform solution. Solution; preparing electrolyte: mixing flour with a weight ratio of 4: 3 to 3.5 and mixing the solution to obtain an electrolyte; preparing electrodes: mixing the solution with a weight ratio of 5: 2.5 to 3: 1 to 1.5, activated carbon and flour The electrode is uniformly obtained; the super capacitor is prepared: the electrolyte is sandwiched between two electrodes to obtain a super capacitor.

Preferably, the weight ratio of phosphoric acid, sodium chloride and deionized water in the solution is 1: 1: 5, the weight ratio of flour in the electrolyte and the solution is 4: 3, and the solution in the electrode The weight ratio of activated carbon and flour is 5: 3: 1.

Preferably, a mold is used to squeeze the electrolyte into a regular shape and then sandwich it between the two electrodes.

Preferably, after the electrode is extruded into the regular shape by using the mold, the electrolyte is sandwiched between the two electrodes.

Preferably, the regular shape is a square plate shape or a cylindrical shape.

Preferably, when the electrode is prepared, the activated carbon and flour are first mixed uniformly, and then added to the solution and mixed uniformly to obtain the electrode.

In another aspect, the present invention provides a one-stop supercapacitor, which includes an electrode and an electrolyte, the electrolyte is sandwiched between the two electrodes, and the electrode includes a weight ratio of 1 to 1.5: 2.5 to 3: 5. : 5:25 to 30 flour, activated carbon, phosphoric acid, sodium chloride, and deionized water, and the electrolyte includes flour, phosphoric acid, sodium chloride, and 4: 3 to 3.5: 3 to 3.5: 15 to 18 by weight. Deionized water.

Preferably, the electrode includes flour having a weight ratio of 1: 3: 5: 5: 25, activated carbon, phosphoric acid, sodium chloride, and deionized water, and the electrolyte includes flour having a weight ratio of 4: 3: 3: 15. , Phosphoric acid, sodium chloride and deionized water.

Preferably, the shape and size of the electrolyte and each of the electrodes are the same.

Preferably, the electrolyte and each of the electrodes are in a square plate shape or a cylindrical shape.

The supercapacitor provided by the invention can perform internal and autonomous self-repair, can be stretched after self-repair, and can be biodegraded after use. The preparation method is simple, the required components are small, and the cost is low. Suitable for flexible and implantable electronic devices.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features of the present invention will become clearer from the following description of the preferred embodiments, which are provided by way of example only in conjunction with the drawings, wherein:

1A is a schematic diagram of preparing an electrolyte and an electrode in a first embodiment of the present invention;

FIG. 1B is a schematic diagram of a self-repair and stretch after repair of a super capacitor in the first embodiment of the present invention; FIG.

1C is a schematic diagram of a biodegradable supercapacitor in the first embodiment of the present invention;

FIG. 2Ai shows the tensile behavior of the electrolyte in the first embodiment of the present invention;

2Aii shows the behavior of the electrolyte in the first embodiment of the present invention undergoing continuous shaping, shearing, repairing, reshaping to the original state and stretching;

FIG. 2Bi shows the stretching behavior of the electrode in the first embodiment of the present invention;

FIG. 2Bii shows the behavior of the electrode in the first embodiment of the present invention undergoing continuous shaping, cutting, repairing, reshaping to the original state and stretching;

2C shows a SEM image of an electrode containing activated carbon and flour in the first embodiment of the present invention;

2D shows a Raman spectrum chart of activated carbon and flour in the first embodiment of the present invention;

FIG. 3A shows each CV curve of the super capacitor in the first embodiment of the present invention at multiple scan rates between 10 mVs ^-1 and 1000 mVs ^-1 ;

3B shows the GCD curves of the super capacitor in the first embodiment of the present invention under a plurality of charge / discharge currents between 5 μA and 20 μA;

4a is a function relationship between the specific capacitance of the supercapacitor and the scan rate between 10 mVs ^-1 and 1000 mVs ^-1 in the first embodiment of the present invention;

4b is a function relationship between the specific capacitance of the ultracapacitor and the current between 5 μA and 20 μA in the first embodiment of the present invention;

5A shows a plurality of CV curves of the supercapacitor from the 0th repair to the 40th repair in the first embodiment of the present invention;

FIG. 5B shows the repair efficiency of the super capacitor in the first embodiment of the present invention from the 0th repair to the 40th repair;

6 shows a plurality of GCD curves of the supercapacitor from the 0th repair to the 40th repair in the first embodiment of the present invention;

7A shows the GCD curves of 0% to 50% stretching of the supercapacitor after self-repair in the first embodiment of the present invention;

FIG. 7B shows a function relationship between capacitance retention and tensile strain of the ultracapacitor in the first embodiment of the present invention; FIG.

FIG. 8 shows the CV curves of the supercapacitor stretched from 0% to 50% after self-repair in the first embodiment of the present invention;

9 is a photo of different tensile strains of the supercapacitor after repairing and repairing in the first embodiment of the present invention;

FIG. 10A shows the biodegradation process of the supercapacitor in the simulated gastric fluid environment in the first embodiment of the present invention; FIG.

FIG. 10B shows the biodegradation process in the supercapacitor nutrient soil in the first embodiment of the present invention.

detailed description

In order to make the purpose and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be clear that the functions of the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

First embodiment

This embodiment provides a one-stop supercapacitor, which includes an electrode and an electrolyte, the electrolyte is sandwiched between the two electrodes, wherein the electrode includes flour and activated carbon with a weight ratio of 1: 3: 5: 5: 25 , Phosphoric acid, sodium chloride, and deionized water, the electrolyte includes flour, phosphoric acid, sodium chloride, and deionized water in a weight ratio of 4: 3: 3: 15. In this embodiment, the shape of the electrolyte and each of the electrodes is a rectangular plate shape, and the sizes are also the same.

The preparation method of the super capacitor includes the following steps:

S1 prepare a solution: 20 g of phosphoric acid, 20 g of sodium chloride and 100 g of deionized water are mixed to obtain a solution.

As shown in FIG. 1A, it is a schematic diagram of preparing an electrolyte and an electrode.

S2 Preparation of electrolyte: 40g of flour and 30g of the solution are mixed to obtain an electrolyte.

S3 Preparation of electrode: 50g of the solution, 30g of activated carbon and 10g of flour are mixed to obtain an electrode. In this embodiment, after the activated carbon and flour are mixed uniformly, then the solution is added to the solution and mixed to obtain the electrode.

S4 prepare a supercapacitor: a supercapacitor is obtained by sandwiching the electrolyte between two electrodes. In this embodiment, the electrolyte and the two electrodes are first extruded into a rectangular plate shape by using the same mold, and then the electrolyte is sandwiched between the two electrodes. In other embodiments, the electrolyte and the two electrodes may be extruded into a cylindrical shape.

In this embodiment, the flour is used as the main material of the electrolyte and the electrode to ensure the excellent flexibility and self-healing properties of the supercapacitor. Phosphoric acid and sodium chloride are used as the ion source to improve the ion conductivity. The combination of activated carbon and flour is used to improve The electronic conductivity of the electrode fully guarantees the electrochemical performance of the supercapacitor. As shown in Figures 1B and 1C, the prepared supercapacitors, through the hydrogen bonds formed between the electrolyte, the flour in the electrodes, and the water molecules, enable the supercapacitors to perform intrinsic and autonomous self-treatment after undergoing mechanical damage such as cutting. It can be repaired, and it can also be stretched after the self-repair. After using the super capacitor, it can be biodegraded. Moreover, the method for preparing supercapacitors is not only simple to prepare, but also requires fewer components and has low cost.

Figure 2Ai shows the tensile behavior of the electrolyte. From this figure, it can be seen that the electrolyte can be shaped into any shape and can be stretched with high strength; Figure 2Aii shows that the electrolyte undergoes continuous shaping, shearing, repair, and reshaping to The original state and stretching behavior can be seen from the figure, the electrolyte can repair itself after being cut, and can be arbitrarily kneaded to completely restore the original shape. More importantly, comparing Figure 2 in Figure 2Ai and Figure 6 in Figure 2Aii, it can be found that the electrolyte after self-repair can be stretched to the same length as the original electrolyte. Similarly, the electrodes also show good flexibility, stretchability, and self-healing properties. The electrode's tensile behavior is shown in Figure 2Bi, and the electrode shown in Figure 2Bii undergoes continuous shaping, shearing, repair, and Forming to the original state and drawing behavior. The unique properties of this electrolyte and electrode make the final supercapacitor also have excellent mechanical stability, that is, it can not only intrinsically and autonomously repair itself, but also perform intrinsic stretching after self-repairing. Figure 2C shows an SEM image of an electrode containing activated carbon and flour. The scale bar is 10um. Micron spherical activated carbon and nanosphere flour can be seen from the figure. This can be verified from Figure 2D. Figure 2D shows the activated carbon and flour. Raman spectrum, where the peaks at 1358.3cm ^-1 and 1593.4cm ^-1 represent the D and G bands of carbon, and the bands at 1580cm ^-1 and 1100 correspond to the aromatic ring vibration and carbon of flour, respectively. Characteristics of acid salts.

FIG. 3A shows each CV curve of the super capacitor at multiple scan rates between 10 mVs ^-1 and 1000 mVs ^-1 , and FIG. 3B shows each GCD curve of the super capacitor at multiple charge / discharge currents between 5 μA and 20 μA. Each electrochemical test is performed at room temperature. FIG. 3A and FIG. 3B show the fast and reversible electrochemical properties of the supercapacitor, which shows that the supercapacitor prepared by the method has good conductivity and effective electrochemical dynamic process. As the scan rate increases, the CV curve gradually deviates from the rectangular shape, which is mainly caused by the diffusion-controlled ion transmission with higher ion transfer resistance at higher rates. As shown in FIGS. 4a and 4b, the specific capacitances of the supercapacitors are calculated from the CV curves of FIG. 3A and the GCD curves of FIG. 3B. Figure 4a shows the relationship between the specific capacitance of the supercapacitor and the scan rate between 10mVs ^-1 and 1000mVs ^-1 . As can be seen from the figure, the calculated capacitance decreases as the scan rate increases. Figure 4b shows the specific capacitance of the supercapacitor as a function of the current between 5 μA and 20 μA. Similarly, the calculated capacitance decreases as the current increases. Among them, the formula for calculating capacitance based on CV curve and GCD curve is as follows:

Where I is the discharge current of the GCD, t is the discharge time of the GCD, U is the voltage range, and U = U ₊ -U _-, s is the area of one of the electrodes, v is the scan rate of the CV curve, i (U) Is the current in CV.

FIG. 5A shows the multiple CV curves of the super capacitor from the 0th repair to the 40th repair, FIG. 5B shows the multiple repair efficiency of the super capacitor from the 0th repair to the 40th repair, and FIG. 6 shows the super capacitor from 0th repair. Multiple GCD curves from the 40th repair to the 40th repair. It can be seen from Figures 5A and 6 that even after 40 times of shearing and repairing, the CV curve and GCD curve of the super capacitor are basically consistent with the curve before repairing, that is, the CV curve and GCD before and after repairing. The high degree of coincidence of the curves indicates that the supercapacitor in this embodiment has a strong self-repairing performance. It can also be seen from FIG. 5B that in all the shearing and repairing processes, the repairing efficiency is about 100%, and the slight fluctuations are mainly due to the inevitable manual connection of the super capacitor during the experiment. These results indicate that the electrolyte and electrode that can be repaired internally are used, so that the supercapacitor in this embodiment can perform self-repair even after 40 times of damage repair to ensure its electrochemical properties, and can be self-repaired many times.

Fig. 7A shows the GCD curves of 0% to 50% stretching after supercapacitor self-repair, Fig. 7B shows the relationship between the capacitance retention and tensile strain of the supercapacitor, and Fig. 8 shows 0% to 10% stretch after supercapacitor self-repair. Each CV curve was stretched by 50%. It can be seen from Figures 7A and 8 that even after stretching to 50% after self-repair, the GCD curve and CV curve are similar to the curve before repair; and from Figure 7B, it can be seen that even after pulling When it reaches 50%, its capacitance remains at about 80%. Although the capacitance decreases slightly with the increase of tensile strain in the figure, it is caused by the slight weakening of the conductivity of the electrode, which is unavoidable. .

Figure 9 is a photo of different tensile strains of the supercapacitor after repair and repair. It can be further verified from the photos that after the supercapacitor is cut, the hydrogen bond can reach a new balance through the contact of the cut surface under the environmental conditions and slight pressure, so that the supercapacitor repairs itself to its original state. And even if it was further stretched to 50%, the supercapacitor did not break and showed strong self-healing and stretchability after self-healing, which had never been achieved before.

FIG. 10A shows the biodegradation process of supercapacitors in a simulated gastric fluid environment, and FIG. 10B shows the biodegradation process of supercapacitors in a nutrient soil. Black blocks are supercapacitors, and bright blocks are plastics used as a control. Since the raw materials used in the super capacitor in this embodiment are non-toxic and environmentally friendly, especially most of them are biodegradable flour, which makes the super capacitor in this embodiment very environmentally friendly and biodegradable. It can be seen from Figure 10A that the supercapacitor was still a whole at first, but after a few days, it was broken down into small pieces, and only carbon powder was left. This is due to the simulation of pepsin in gastric juice to protein in flour. Caused by decomposition. Similarly, supercapacitors in nutrient soils are gradually decomposed. This is mainly due to the microorganisms in the soil transforming the organic substances in the supercapacitors into inorganic substances to achieve degradation. This fully verified the biodegradability and environmental protection of the ultracapacitor in this embodiment.

Second embodiment

The same parts of this embodiment as those of the first embodiment have been omitted. The different part is that when preparing a super capacitor, the solution in step S1 is prepared by mixing 20g phosphoric acid, 20g sodium chloride and 120g deionized water. In S2, the electrolyte is prepared by mixing 40g of flour and 35g of the solution, and in step S3, the electrode is prepared by mixing 50g of the solution, 25g of activated carbon, and 15g of flour.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. within.

Claims

The method for preparing a one-stop supercapacitor is characterized in that it includes the following steps:

Preparation of solution: phosphoric acid, sodium chloride and deionized water in a weight ratio of 1: 1: 5 to 6 are mixed uniformly to obtain a solution;

Preparing electrolyte: mixing flour with a weight ratio of 4: 3 to 3.5 and the solution to obtain an electrolyte;

Preparing an electrode: mixing the solution, activated carbon and flour in a weight ratio of 5: 2.5 to 3: 1 to 1.5 to obtain an electrode;

Preparation of a super capacitor: a super capacitor is obtained by sandwiching the electrolyte between two electrodes.
The preparation method according to claim 1, wherein a weight ratio of phosphoric acid, sodium chloride and deionized water in the solution is 1: 1: 5, and a weight ratio of flour in the electrolyte to the solution is 4: 3, the weight ratio of the solution, activated carbon and flour in the electrode is 5: 3: 1.
The method according to claim 1, wherein the electrolyte is extruded into a regular shape by a mold and then sandwiched between the two electrodes.
The method according to claim 3, wherein after the electrode is extruded into the regular shape by using the mold, the electrolyte is sandwiched between the two electrodes.
The preparation method according to claim 3 or 4, wherein the regular shape is a square plate shape or a cylindrical shape.
The preparation method according to any one of claims 1 to 4, characterized in that, when preparing an electrode, the activated carbon and flour are first mixed uniformly, and then added to the solution and mixed to obtain the electrode.
The one-stop supercapacitor includes an electrode and an electrolyte, and the electrolyte is sandwiched between the two electrodes, wherein the electrode includes a weight ratio of 1 to 1.5: 2.5 to 3: 5: 5: 25 to 30 Flour, activated carbon, phosphoric acid, sodium chloride, and deionized water, the electrolyte includes flour, phosphoric acid, sodium chloride, and deionized water in a weight ratio of 4: 3 to 3.5: 3 to 3.5: 15 to 18.
The one-stop supercapacitor according to claim 7, wherein the electrode comprises flour, activated carbon, phosphoric acid, sodium chloride, and deionized water in a weight ratio of 1: 3: 5: 5: 25, and The electrolyte includes flour, phosphoric acid, sodium chloride, and deionized water in a weight ratio of 4: 3: 3: 15.
The one-stop supercapacitor according to claim 7, wherein the shape and size of the electrolyte and each of the electrodes are the same.
The one-stop supercapacitor according to any one of claims 7 to 9, wherein the electrolyte and each of the electrodes are in a square plate shape or a cylindrical shape.