CN102270761A - A kind of preparation method of flexible integrated organic radical electrode - Google Patents

Abstract

The invention discloses a method for preparing a flexible and integrated organic radical electrode, which comprises the following steps: step 1: using a microwave oven to modify carbon cloth for 1 hour and cleaning; step 2: dissolving the organic radical polymer material In N-methyl-pyrrolidone solvent, and soak the treated carbon cloth in the solution for 4 hours; step 3: under the condition of 60 ℃, evaporate the solution in a vacuum oven to make an electrode; step 4 : Assembling with the prepared composite electrode, and performing charge and discharge treatment. The organic free radical flexible electrode prepared by the method of the present invention has the characteristics of large active material load, good flexibility, bendability, long cycle life, high power, low cost and no environmental pollution when used, and has opened up A new method for the preparation of an all-in-one organic radical flexible electrode without conductive agents.

Description

A kind of preparation method of flexible integrated organic radical electrode

technical field

The invention relates to the technical field of electrochemical energy storage, in particular to a method for preparing a flexible integrated organic radical electrode.

Background technique

Since 2002, K.Nakahara has reported a kind of novel organic macromolecule nitroxide free radical material as the anode material of rechargeable battery (please refer to the literature Chemical Physics Letters 359 (2002) 351-354), numerous relevant patents have reported Application of various batteries using nitrogen-oxygen radical materials as electrode materials. At the same time, NEC Corporation of Japan has also launched an organic radical battery using organic radical polymer materials as the positive electrode material. This battery has many advantages such as long cycle life, fast charge and discharge rate, good processability, and environmental friendliness. It has been applied in electronic products, electronic industry, communication industry, military field and so on.

How to use organic polymer free radicals to prepare rechargeable batteries has become a rising technology in the industry. For example, the Chinese invention patent with application number 200710035972.4 discloses a method for preparing lithium batteries using organic free radical polymers. The preparation characteristics of the positive plate The prepared slurry is applied on an aluminum foil with a coating machine and dried, and then cut into a positive electrode sheet.

But all there is following defective in above-mentioned patent and the method for preparing battery of prior art:

First of all, since the organic radical polymer material is a redox polymer, the intrinsic conductivity is very poor. In the traditional electrode preparation, a large amount of conductive agent (such as expensive vapor-deposited carbon nanofibers) needs to be added. to 50% of the heavy mass of the electrode, which greatly reduces the overall energy density of the electrode;

Secondly, it is also necessary to disperse the polymer and the conductive agent well, and then coat it on the metal current collector. This not only requires a cumbersome process, but also puts forward higher requirements for the equipment;

Thirdly, coating on the traditional metal foil will affect the flexibility of the electrode and reduce the bendability of the electrode, which greatly limits the scope of use of the electrode.

Therefore, in order to enable the organic radical battery to be applied in a wide space, it is urgent to improve the preparation method of the electrode. .

Contents of the invention

In view of the above defects, the purpose of the present invention is to provide a flexible integrated organic radical electrode preparation method to solve the technical problems of low overall energy density, poor bending performance and cumbersome preparation process of the battery prepared in the prior art.

To achieve the above object, the present invention adopts the following technical solutions:

A method for preparing a flexible integrated organic radical electrode, comprising the following steps:

Step 1: Use a microwave oven to modify the carbon cloth for 1 hour and clean it;

Step 2: dissolving the organic radical polymer material in N-methyl-pyrrolidone solvent, and immersing the treated carbon cloth in the solution for 4 hours;

Step 3: Evaporate the solution in a vacuum oven at 60°C to prepare an electrode;

Step 4: Assemble with the prepared composite electrode, and perform charge and discharge treatment.

According to the preparation method of the flexible integrated organic radical electrode described in the preferred embodiment of the present invention, the step 1 further includes: step 1.1: soaking a 10cmx10cm square carbon cloth in a 1M alkaline solution, and performing microwave modification The microwave power is 1000W.

According to the preparation method of the flexible integrated organic radical electrode described in the preferred embodiment of the present invention, the step 1 further includes: step 1.1: immersing a 10cmx10cm square carbon cloth in a 1M _ZnCl2 solution, and performing microwave modification The microwave power is 1000W.

According to the method for preparing a flexible integrated organic radical electrode described in a preferred embodiment of the present invention, the organic radical polymer material is a polynorbornene derivative organic radical polymer material or poly-4-methacryloyl One of the oxy-2,2,6,6-tetramethyl-piperidinol nitroxide radicals.

According to the preparation method of the flexible integrated organic radical electrode described in the preferred embodiment of the present invention, the step 4 further includes: step 4.1: punching the prepared composite electrode into a small disc with a diameter of 14 mm as the positive electrode, and using metal Lithium sheet as the negative electrode, with 1M LiPF ₆ /EC-DEC as the electrolyte, assembled in a 2016 button battery; step 4.2: charge and discharge between 2-4V, the charging platform is around 3.6V, and discharge The capacity is around 3.6V.

According to the preparation method of the flexible integrated organic radical electrode described in the preferred embodiment of the present invention, the volume ratio of 1M LiPF ₆ /EC-DEC in the electrolyte is 3:7.

According to the method for preparing a flexible integrated organic radical electrode described in a preferred embodiment of the present invention, the carbon cloth includes carbon paper, carbon felt, and cloth or paper made of various carbon materials such as carbon nanotubes, carbon fibers, or graphene. .

According to the method for preparing a flexible integrated organic radical electrode described in a preferred embodiment of the present invention, the alkaline solution is one of NaOH, LiOH, and KOH.

According to the preparation method of the flexible integrated organic radical electrode described in the preferred embodiment of the present invention, in step 4, the discharge capacity of 1C is 101mAh/g or 107mAh/g.

Owing to adopting above technical feature, make method of the present invention have following advantage and positive effect relative to prior art:

First of all, the organic free radical flexible electrode prepared according to the method of the present invention has the characteristics of large active material loading, good flexibility, bendability, long cycle life, high power, low cost and no environmental pollution when used. Opened up a new method for the preparation of an integrated organic radical flexible electrode without a conductive agent;

Secondly, the carbon cloth modification method proposed by the present invention can greatly improve the micropores of the carbon cloth, and change the surface characteristics of the carbon cloth, thereby facilitating the adhesion of organic radical polymers on the carbon cloth and improving the active material. The loading capacity increases the energy density of the electrode;

Thirdly, the method of the present invention uses carbon cloth as the current collector and conductor, and relies on the viscosity of the polymer itself or the viscosity of the added binder to directly compound with the organic free radical polymer, and the preparation process is simple. At the same time, the electrode prepared in this way has good flexibility and high energy density.

Description of drawings

Fig. 1 is the flow chart of preparation method of the present invention;

FIG. 2 is a charge-discharge curve of the second embodiment of the present invention.

Detailed ways

Several preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. The present invention covers any alternatives, modifications, equivalent methods and schemes made on the spirit and scope of the present invention. In order to provide the public with a thorough understanding of the present invention, specific details are set forth in the following preferred embodiments of the present invention, but those skilled in the art can fully understand the present invention without the description of these details.

The core of the present invention is to provide a method for preparing a flexible organic radical electrode, using microwave-modified porous carbon cloth as a current collector, and preparing a flexible organic radical electrode without a conductive agent. The organic free radical flexible electrode prepared by the present invention has the characteristics of large active material load, good flexibility, bendability, long cycle life, high power, low cost and no environmental pollution when used, and has opened up a new field that does not contain A New Method for the Preparation of Integrated Organic Radical Flexible Electrodes with Conductive Agents

Please refer to Fig. 1, which is a flow chart of the method of the present invention, and the preparation method of the flexible organic radical electrode provided by the present invention includes:

S101: Use a microwave oven to modify the carbon cloth for 1 hour and clean it;

Carbon cloth is a variety of commercial carbon cloth, carbon paper, and carbon felt, including self-prepared carbon cloth, carbon felt, and cloth or paper made of various carbon materials such as carbon nanotubes, carbon fibers, or graphene.

Immerse the carbon cloth in a certain concentration of alkaline, acidic or salt solution or organic solution, and modify it by microwave at a certain power for a certain period of time. Then, the carbon cloth is washed to increase the number of micropores of the carbon cloth, thereby greatly increasing the reaction area of the electrode, thereby increasing the loading capacity of the organic free radical active material.

Alkaline solutions include NaOH, LiOH, KOH and other alkaline solutions, acidic solutions include sulfuric acid, nitric acid, phosphoric acid, acetic acid, etc., salts include zinc chloride, sodium chloride, sodium carbonate and other salts, organic systems include quaternary ammonium salt solutions, etc. Organic solvents for dissolving organic radical polymer materials include acetonitrile, N-methyl-pyrrolidone, dichloromethane and other more polar solvents.

S102: dissolving the organic radical polymer material in N-methyl-pyrrolidone solvent, and immersing the treated carbon cloth in the solution for 4 hours;

S103: Evaporate the solution in a vacuum oven under the condition of 60° C. to prepare an electrode;

Preparation of composite electrode: dissolve the organic free radical polymer material (or add a certain amount of binder) in the solvent, then soak the treated carbon cloth in the solution for a certain period of time, and slowly evaporate the solvent to obtain electrode.

The prepared composite electrodes can be used as positive or negative electrodes of organic free radicals according to different types of organic free radical polymers (p-doped or n-doped type).

S104: Assembling with the prepared composite electrode, and performing charge and discharge treatment.

Two specific embodiments of the present invention are described below in conjunction with the accompanying drawings.

Embodiment one

This embodiment is a kind of polynorbornene derivative organic radical polymer material (hereinafter referred to as PNBT) (poly(NB-2,3-endo, exo-(COO-4-(2,2,6,6 -tetramethylpiperidine-1-oxy)) ₂ )) as the positive electrode active material and carbon cloth for composite.

The specific implementation method is:

(1) Modification of the carbon cloth with a microwave oven used in ordinary households: immerse a 10cmX10cm square carbon cloth in 100ml, 1M LiOH solution, and modify it by microwave at a power of 1000W for 1 hour. The carbon cloth is then washed.

(2) Preparation of composite electrode: Dissolve 0.5g polynorbornene derivative organic radical polymer material in N-methyl-pyrrolidone solvent, and then immerse the treated 0.5g carbon cloth in the solution for 4 hours , At 60C, the solvent was slowly evaporated in a vacuum oven to prepare an electrode.

The prepared composite electrode was punched into a small disc with a diameter of 14 mm as the positive electrode, a metal lithium sheet was used as the negative electrode, and 1M LiPF ₆ /EC-DEC (volume ratio 3:7) was used as the electrolyte, and assembled in a battery configuration of 2016 button type battery.

Charge and discharge between 2-4V, the charging platform is about 3.6V, and the discharge capacity is about 3.6V, and the 1C discharge capacity is 107mAh/g (the calculation capacity here only considers the PNBT capacity, and its charge and discharge curve is shown in Figure 2 .

Embodiment two

This embodiment is an organic free radical macromolecular material poly 4-methacryloyloxy-2,2,6,6-tetramethyl-piperidinol nitroxide free radical (Poly 2,2,6, 6-tetramethylpiperidine-1-oxymethacrylate)) (hereinafter referred to as PTMA) is used as the positive electrode active material and carbon cloth to prepare the method for composite electrode.

The specific implementation method is:

(1) Modification of the carbon cloth using a microwave oven used in ordinary households: immerse a 10cmX10cm square carbon cloth in 100ml, 1M ZnCl ₂ solution, and modify it by microwave at a power of 1000W for 1 hour. The carbon cloth is then washed.

(2) Preparation of composite electrode: Dissolve 0.5g PTMA organic free radical macromolecular material in N-methyl-pyrrolidone solvent, then soak the treated 0.5g carbon cloth in the solution for 4 hours, at 60°C , the solvent was slowly evaporated in a vacuum oven to prepare the electrode.

The prepared composite electrode was punched into a small disc with a diameter of 14 mm as the positive electrode, a metal lithium sheet was used as the negative electrode, and 1M LiPF ₆ /EC-DEC (volume ratio 3:7) was used as the electrolyte, and assembled in a battery configuration of 2016 button type battery. Charging and discharging between 2-4V, the charging platform is about 3.6V, and the discharge capacity is about 3.6V, and the 1C discharge capacity is 101mAh/g (the calculation capacity here only considers the PNBT capacity).

In summary, due to the adoption of the above technical characteristics, the method of the present invention has the following advantages and positive effects compared to the prior art: First, the organic free radical flexible electrode prepared according to the method of the present invention has an active material loading capacity Large, flexible, bendable, long cycle life, high power, low cost and no environmental pollution when used, opened up a new method for the preparation of integrated organic radical flexible electrodes without conductive agents;

Secondly, the carbon cloth modification method proposed in the present invention can greatly improve the micropores of the carbon cloth, and change the surface characteristics of the carbon cloth, thereby facilitating the adhesion of organic free radical polymers on the carbon cloth and improving the active material. The loading capacity increases the energy density of the electrode;

Thirdly, the method of the present invention uses carbon cloth as the current collector and conductor, and relies on the viscosity of the polymer itself or the viscosity of the added binder to directly compound with the organic free radical polymer, and the preparation process is simple. At the same time, the electrode prepared in this way has good flexibility and high energy density.

The preferred embodiments of the invention are provided only to help illustrate the invention. The preferred embodiments are not exhaustive in all detail, nor are the inventions limited to specific embodiments described. Obviously, many modifications and variations can be made based on the contents of this specification. This description selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention. The invention is to be limited only by the claims, along with their full scope and equivalents.

Claims (9)

1. the preparation method of the integrated organic free radical electrode of flexibility is characterized in that, may further comprise the steps:

Step 1: use microwave oven that carbon cloth is carried out modification and handled 1 hour, and clean;

Step 2: the organic free radical macromolecular material is dissolved in N-methyl-pyrrolidones solvent, and the carbon cloth that will handle is immersed in the solution and continues 4 hours;

Step 3: under 60 ℃ condition, in vacuum drying oven, solution is evaporated, to make electrode;

Step 4: assemble with the combination electrode that makes, and discharge and recharge processing.

2. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 1 is characterized in that described step 1 further comprises:

Step 1.1: the square carbon cloth of 10cmx10cm is immersed in the alkaline solution of 1M, and the microwave power that carries out microwave modification is 1000W.

3. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 1 is characterized in that described step 1 further comprises:

Step 1.1: the ZnCl that the square carbon cloth of 10cmx10cm is immersed in 1M ₂Solution, the microwave power that carries out microwave modification is 1000W.

4. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 1, it is characterized in that, described organic free radical macromolecular material is polynorbornene derivatives organic free radical macromolecular material or poly-4-methacryloxy-2,2,6,6-tetramethyl-piperidinol nitroxyl radical one of them.

5. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 1 is characterized in that, further comprises in described step 4:

Step 4.1: will prepare sequin that the gained combination electrode is washed into diameter 14mm as positive pole, with metal lithium sheet as negative pole, with 1M LiPF ₆/ EC-DEC is as electrolyte, and being assemblied in battery configuration is in 2016 button cells;

Step 4.2: discharge and recharge between 2-4V, charging platform is about 3.6V, and discharge capacity is about 3.6V.

6. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 5 is characterized in that, 1M LiPF in the described electrolyte ₆The volume ratio of/EC-DEC is 3: 7.

7. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 1 is characterized in that, described carbon cloth comprises the cloth or the paper of various material with carbon element preparations such as carbon paper, carbon felt and carbon nano-tube, carbon fiber or Graphene etc.

8. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 2 is characterized in that, described alkaline solution be NaOH, LiOH, KOH one of them.

9. the preparation method of the integrated organic free radical electrode of flexibility as claimed in claim 1 is characterized in that, in step 4, the discharge capacity of 1C is 101mAh/g or 107mAh/g.

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