WO2018184183A1

WO2018184183A1 - Method of manufacturing lithium-ion battery electrode and assembling battery

Info

Publication number: WO2018184183A1
Application number: PCT/CN2017/079651
Authority: WO
Inventors: 钟玲珑
Original assignee: 深圳市佩成科技有限责任公司
Priority date: 2017-04-07
Filing date: 2017-04-07
Publication date: 2018-10-11

Abstract

Provided in the present invention are a method of manufacturing a lithium-ion battery electrode, and assembling a battery. The method comprises: performing microwave synthesis, employing a synthesized Fe2O3 nano-material as an electrode active material, selecting a conductive agent and binder, adding N-methylpyrrolidone as an solvent proportionally, and acquiring a paste by means of grinding and mixing; coating the paste on a copper foil of a current collector, vacuum drying, removing the solvent and moisture, and performing compaction to enable contact tightness between an electrode and a powder material; and performing stamping to obtain a negative electrode disk, and drying in a vacuum drying chamber in preparation for battery assembly. The method of manufacturing a lithium-ion battery electrode and assembling a battery provided by the present invention provides a superior capacitive characteristic and conductive property to a manufactured electrode of a lithium-ion battery. In addition, the method improves a utilization rate of an electrode material, thus improving a capacity of the material.

Description

Lithium ion battery electrode preparation and battery assembly method

[0001] The present invention relates to a lithium ion battery electrode preparation and a battery assembly method, and belongs to the field of nano material preparation.

Background technique

[0002] Iron oxide nanomaterials are widely used in catalysts, energy storage and conversion equipment, magnetic materials, water pollution treatment, gas sensitive materials, pigments, etc. due to their excellent properties. The supercapacitor has the advantages of high power density, fast charge and discharge speed, good cycle stability and long life. As a new type of energy storage device, it has attracted more and more attention. Based on the research status of iron oxide nanomaterials, this paper mainly attempts to synthesize a variety of iron oxide nanomaterials, such as one-dimensional nanostructures, hollow structures, polyhedral structures, and other X-based synthetic methods. Modern analytical testing techniques such as ray diffraction (XRD), scanning electron microscopy (S EM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and specific surface tester (BET) characterize the microstructure of materials. Appearance and structure, respectively, using the prepared iron oxide nanomaterials as supercapacitor and lithium ion battery electrode materials, assembled into test devices, using cyclic voltammetry, AC impedance, constant current charge and discharge test methods to study the electrochemical properties of the material, I got good test results.

technical problem

[0003] As a new type of energy storage device, the supercapacitor has the advantages of high output power, short charging time, wide operating temperature range, long service life, safety and no pollution, and is expected to become a new green power source in this century. At present, commonly used materials for supercapacitor electrodes include carbon materials, metal oxide materials, conductive polymer materials, etc., but these materials have inherent problems, resulting in a relatively low specific capacity of the electrode material, which is bound to be a capacitor. The overall performance has a big impact.

Problem solution

Technical solution

In view of the above deficiencies of the prior art, an object of the present invention is to provide a method for preparing a lithium ion battery electrode and assembling the battery. [0005] The object of the present invention is to overcome the deficiencies of the materials prepared by the conventional preparation method, and to provide a lithium ion battery electrode preparation and a battery assembly method. In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a lithium ion battery electrode preparation and battery assembly method, comprising the following steps: [0007] Step one, microwave synthesis, respectively, Fe(N0 ₃ ) ₃ 9H ₂ 0 and KOH are dissolved in deionized After stirring, the mixed solution is transferred to a microwave reactor for reaction; after natural cooling, the obtained precipitate is centrifuged and washed repeatedly; after vacuum drying, the yellow-green product is obtained as oc-FeOOH; the product is heated and then naturally cooled, and finally red is obtained. The product is ot-Fe ₂ 0 ₃ ;

[0008] Less _■, using synthetic Fe203 nanomaterial as electrode active material, selecting a conductive agent and a binder, adding N-methylpyrrolidone solvent in proportion, and grinding and mixing to obtain a slurry;

[0009] Step three, the slurry is coated on the current collector copper foil, and then dried in a vacuum, the solvent and moisture are removed, and compacted to make the electrode powder contact tight;

[0010] Step 4. Pressing into a negative electrode wafer, and drying in a vacuum drying oven to prepare a battery assembly.

[0011] Preferably, the foregoing step one specifically includes:

[0012] Step 1.1, respectively, dissolved Fe(NO ₃ ) 3-9H ₂ 0 and KOH in deionized water;

[0013] Step 1.2, the KOH solution is added dropwise to the stirred Fe(NO ₃ ) ₃ ·9Η ₂₀ solution;

[0014] Step 1.3, adding deionized water to the mixed solution, after stirring, transferring the mixed solution into a three-necked flask;

[0015] Step 1.4, a three-necked flask containing the solution is reacted in a microwave reactor;

[0016] Step 1.5, after the reaction is completed, the flask is naturally cooled to room temperature, and the obtained precipitate is centrifuged, and repeatedly washed with anhydrous ethanol and distilled water to remove the unreacted reagent;

[0017] Step 1.6, the washed precipitate is vacuum dried to obtain a yellow-green product is ot-FeOOH;

[0018] Step 1.7, the product was then placed in a muffle furnace, warmed to 350 ° C, and then naturally cooled to room temperature, finally resulting in a dry, loose red product of oc-Fe ₂ 0 ₃ .

[0019] Preferably, in the above step 1.1, 0.02 mol of Fe(NO ₃ ) ₃ ·9Η ₂ 0 and 0.02 mol of KOH, respectively.

Dissolved in 20 ml of deionized water.

[0020] Preferably, 30 ml of deionized water is added to the mixed solution in the above step 1.3, and after stirring for 10 minutes, the mixed solution is transferred into a three-necked flask.

[0021] Preferably, in the above step 1.4, the three-necked flask containing the solution is at 90. 1 small reaction in C microwave reactor Inches.

[0022] Preferably, in the above step 2, the conductive agent is carbon black, and the binder is polyvinylidene fluoride, and the mass ratio is 75.

: 20:5 ratio electrode active, conductive agent and binder.

[0023] Preferably, the third step is specifically to apply the slurry on the current collector copper foil, and then vacuum drying at 120 ° C for 8 to 10 hours to remove the solvent and moisture, and under the pressure of 8-12 MPa. Compaction, making the electrode powder contact tight.

[0024] Preferably, the above step 4 is specifically pressing a negative electrode wafer having a diameter of 10 mm, and drying the battery in a vacuum drying oven for 8 to 10 hours.

[0025] Preferably, the above battery is assembled in a dry glove box filled with argon gas.

Advantageous effects of the invention

Beneficial effect

The invention provides a lithium ion battery electrode preparation method and a battery assembly method, and the prepared lithium ion battery has obvious electrode capacitance characteristics and good electrical conductivity, and the method improves the utilization rate of the electrode material, thereby improving the material capacity.

Brief description of the drawing

DRAWINGS

1 is a schematic diagram of the cyclic voltammetry curve without PVP at different scanning rates of ot-FeOOH prepared according to the present invention.

2 is a schematic diagram of the addition of PVP to cyclic voltammetry curves of ot-FeOOH prepared at different scanning rates according to the present invention.

Embodiments of the invention

The present invention provides a lithium ion battery electrode preparation and a battery assembly method. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0030] The lithium ion battery electrode preparation and the battery assembly method provided by the embodiment specifically include the following steps: [0031] Microwave synthesis, firstly dissolving 0.02 mol of Fe(NO ₃ ) ₃ ·9Η ₂ 0 and 0.02 mol KOH, respectively. Going away at 20ml Sub-water. The KOH solution was then added dropwise to the stirred Fe(N0 ₃ ) ₃ 9H ₂ 0 solution. B30 ml of deionized water was added to the mixed solution, and after stirring for 10 minutes, the mixed solution was transferred to a three-necked flask. The three-necked flask containing the solution was reacted for 1 hour in a microwave reactor at 90 °C. After the completion of the reaction, the flask was naturally cooled to room temperature, and the resulting precipitate was centrifuged, and washed repeatedly with absolute ethanol and distilled water to remove the unreacted reagent. The washed precipitate was vacuum dried at 60 ° C for 8 h to give a yellow-green product as a-FeOOH. The product was then placed in a muffle furnace, warmed to 350 ° C for 3 hours, then naturally cooled to room temperature, and finally a dry, loose red product was obtained as oc-Fe ₂ 0 ₃

Synthetic Fe203 nanomaterials were used as electrode active materials, carbon black was used as conductive agent, and polyvinylidene fluoride (PVDF) was used as binder. N-methylpyrrolidone (NMP) solvent was added in proportion (mass ratio: 75:20:5). Thereafter, the slurry was obtained by grinding and mixing. Apply the slurry to the current collector copper foil, then 120

Dry at 8 °C for 8~10 hours under vacuum, remove the solvent and moisture, and compact at a pressure of 8~12MPa to make the electrode powder contact tightly. Re-punched into a diameter of 10

A negative electrode wafer of mm size was prepared by drying in a vacuum oven for 8-10 hours. The battery was assembled in a dry glove box filled with argon. The test cell uses a CR2025 button cell, the positive electrode uses a metal lithium plate, the diaphragm uses a Celgard 2325 film, and the electrolyte is a 1 M LiPF6 EC: DMC = 1:1 (volume ratio) electrolyte.

[0033] Cyclic voltammetry is a common method for studying the electrochemical behavior of electrodes in electrolyte systems. Cyclic voltammetry can be used to test the change of current with charge and discharge voltage during supercharger electrode material charging and discharging. The test principle is as follows: A linearly-variable periodic scanning potential signal is applied to the electrode, and the current response value in the circuit is detected, and information on the electrode condition required for the experiment is obtained from the obtained spectrum. Such as the reversibility of the electrode, charge and discharge performance, oxygen evolution characteristics, electrode material and electrolyte ion exchange charge characteristics.

1 and 2 are cyclic voltammograms of α-FeOOH materials without PVP and PVP, respectively, and the scanning rate is increased from 5 mV s -1 to 100 mV s -1 , and the scanning voltage range is - 0.01-0.8V. It can be seen from the figure that the cyclic voltammograms of the two materials are not much different. The respective CV curves have a pair of distinct redox peaks instead of a rectangular-like shape, indicating that this is a distinct Faraday tantalum capacitor. Instead of electric double layer capacitors. As the scanning rate increases, the voltage difference between the oxidation peak and the reduction peak becomes larger and larger, which indicates that as the scanning rate increases, the reaction becomes more and more difficult, mainly due to the polarization of the electrode. of.

[0035]

The preparation of the lithium ion battery electrode and the assembly method of the battery provided by the invention have the characteristics of excellent capacitance and good electrical conductivity of the lithium ion battery, and the method improves the utilization rate of the electrode material and thereby increases the capacity of the material.

[0037]

[0038] It is to be understood that those skilled in the art can make equivalent substitutions or changes in accordance with the present invention and the inventive concept, and all such changes or substitutions should be included in the appended claims. protected range.

Claims

Claim

[Claim 1] A method for preparing a lithium ion battery electrode and assembling the battery, the method comprising the steps of:

Step 1. Microwave synthesis, dissolving Fe(N0 ₃ ) ₃ , 9H ₂ 0 and KOH in deionized water, respectively

After stirring, the mixed solution is transferred to a microwave reactor for reaction; after natural cooling, the obtained precipitate is centrifuged and washed repeatedly; after vacuum drying, a yellow-green product is obtained as oc-FeOOH; the product is heated and then naturally cooled, and finally a red product is obtained. oc-Fe ₂ 0 ₃ ; Step 2, using Fe203 nanomaterial as electrode active material, selecting conductive agent and binder

After adding the N-methylpyrrolidone solvent in proportion, after grinding and mixing to obtain a slurry; Step 3, applying the slurry to the current collector copper foil, drying in a vacuum, removing the solvent and moisture, and compacting the electrode Close contact between powders;

Step 4: Pressing into a negative electrode wafer, and drying in a vacuum drying oven to prepare a battery assembly.

[Claim 2] The method for preparing a lithium ion battery electrode and the battery assembly method according to claim 1, wherein: the step one specifically includes:

Step 1.1: Dissolve Fe(NO ₃ ) 3-9H ₂ 0 and KOH in deionized water respectively; Step 1.2, add the KOH solution to the stirred Fe(NO ₃ ) ₃ ·9Η ₂ 0 solution; Step 1.3 Add deionized water to the mixed solution, and after stirring, transfer the mixed solution to a three-necked flask;

Step 1.4: The three-necked flask containing the solution is reacted in a microwave reactor;

Step 1.5 After the reaction is completed, the flask is naturally cooled to room temperature, and the resulting precipitate is centrifuged.

Repeated washing with absolute ethanol and distilled water to remove the unreacted reagent; Step 1.6, vacuum drying the washed precipitate to obtain a yellow-green product of oc-FeOOH; Step 1.7, then placing the product into a muffle furnace The temperature was raised to 350 ° C to maintain, and then naturally cooled to room temperature, and finally the dry loose red product was obtained as oc-Fe ₂ 0 ₃ .

[Claim 3] The method for preparing a lithium ion battery electrode and assembling the battery according to claim 2, wherein: in the step 1.1, 0.02 mol of Fe(NO ₃ ) ₃ ·9Η ₂ 0 and 0.02 mol of KOH, respectively Dissolved in 20 ml of deionized water.

[Claim 4] The method for preparing a lithium ion battery electrode and assembling the battery according to claim 2, characterized in that In the step 1.3, 30 ml of deionized water was added to the mixed solution, and after stirring for 10 minutes, the mixed solution was transferred to a three-necked flask.

[Claim 5] The lithium ion battery electrode preparation and battery assembly method according to claim 2, wherein: in the step 1.4, a three-necked flask containing a solution is at 90. The reaction was carried out for 1 hour in a microwave reactor of C.

[Claim 6] The method for preparing a lithium ion battery electrode and assembling the battery according to claim 1, wherein: in the second step, the conductive agent is carbon black, and the binder is polyvinylidene fluoride, according to the mass ratio. It is a ratio of 75:20:5 electrode active, conductive agent and binder.

[Claim 7] The method for preparing a lithium ion battery electrode and assembling the battery according to claim 1, wherein the step 3 is specifically applying the slurry to a current collector copper foil at 120 ° C. Dry under vacuum for 8~10 hours, remove solvent and moisture, and compact under the pressure of 8~12MPa to make the electrode powder contact tightly.

[Claim 8] The method for preparing a lithium ion battery electrode and assembling the battery according to claim 1, wherein: the step 4 is specifically pressing a negative electrode wafer having a diameter of 10 mm, in a vacuum drying oven. Prepare the battery assembly after drying for 8-10 hours.

[Claim 9] The lithium ion battery electrode preparation and battery assembly method according to claim 8, wherein the battery is assembled in a dry glove box filled with argon gas.