阅读说明：本技术 一种高质量石墨烯电池的制备方法 (Preparation method of high-quality graphene battery ) 是由 巫洋 邱艳遐 马海冬 于 2021-08-03 设计创作，主要内容包括：本发明提供一种高质量石墨烯电池的制备方法,包括以下步骤：S10、石墨烯材料制备；S20、负极浆料制备；S30、正极浆料制备；S40、浆料涂布；S50、电池装配。本发明提供一种高质量石墨烯电池的制备方法,石墨烯是碳原子基于sp2杂化组成的六角蜂巢状结构,仅一个原子层厚的二维晶体,在电学、光学、热学力学等方面均呈现出优异的性能。钛酸锂电池负极导电性能差,但是石墨烯与钛酸锂复合可以有效的提高电池材料的活性物质比,更重要的是在提高倍率性能的同时可以提高其循环性能。(The invention provides a preparation method of a high-quality graphene battery, which comprises the following steps: s10, preparing a graphene material; s20, preparing negative electrode slurry; s30, preparing positive electrode slurry; s40, coating slurry; and S50, assembling the battery. The invention provides a preparation method of a high-quality graphene battery, wherein graphene is a hexagonal honeycomb structure formed by hybridizing carbon atoms based on sp2, is a two-dimensional crystal with the thickness of only one atomic layer, and has excellent performances in the aspects of electricity, optics, thermal mechanics and the like. The lithium titanate battery cathode has poor conductivity, but the graphene and lithium titanate composite material can effectively improve the active substance ratio of the battery material, and more importantly, the rate performance can be improved while the cycle performance can be improved.)

1. A preparation method of a high-quality graphene battery is characterized by comprising the following steps:

s10, preparing a graphene material: processing a graphite raw material step by step to obtain graphene powder;

s20, preparing anode slurry: compounding the graphene powder obtained in the step S10 with a lithium titanate negative electrode material by a sol-gel method, adding the prepared graphene powder into a conductive agent, and homogenizing by combining a binder to obtain negative electrode slurry;

s30, preparing positive electrode slurry: homogenizing a lithium manganate positive electrode material, a binder and a conductive agent to obtain positive electrode slurry;

s40, slurry coating: coating the negative electrode slurry prepared in the step S20 on a negative electrode sheet, and coating the positive electrode slurry prepared in the step S30 on a positive electrode sheet;

s50, assembling the battery: and (4) rolling and shearing the negative pole piece and the positive pole piece prepared in the step (S40), and assembling the negative pole piece and the positive pole piece into a battery frame.

2. The method for preparing a high-quality graphene battery according to claim 1, wherein the method comprises the following steps: in step S10, the graphene material preparation includes the following steps:

s11, pretreatment of graphite raw materials: stirring and mixing a graphite raw material and an organic solvent, filtering, and carrying out high-temperature treatment on a graphite filter cake obtained by filtering under the protection of inert gas;

s12, graphite oxidation treatment: adding the graphite raw material pretreated in the step S11 and an auxiliary oxidant into an alkali solution, placing the mixture into a closed space, introducing oxidation into the closed space to a certain pressure for reaction, and performing solid-liquid separation after the reaction is finished to obtain a solid phase, namely graphene oxide;

s13, reducing graphene oxide: preparing the graphene oxide prepared in the step S12 into a graphene oxide aqueous solution, adjusting the pH, and carrying out reduction reaction on the graphene oxide aqueous solution under the irradiation of ultraviolet light;

s14, post-processing: and (4) filtering and drying the aqueous solution obtained after the reduction in the step S13 to obtain graphene powder.

3. The method for preparing a high-quality graphene battery according to claim 1, wherein the method comprises the following steps: in step S40, when the positive electrode tab and the negative electrode tab are coated with the slurry, empty foils are left on both the upper and lower sides of the positive electrode tab and the negative electrode tab.

4. The method for preparing a high-quality graphene battery according to claim 2, wherein the method comprises the following steps: in step S11, adding a graphite raw material and an organic solvent N-dimethylformamide solvent into a high-pressure reaction kettle, heating to 170 ℃, and stirring for 4 hours; and after cooling, taking out the graphite raw material, filtering to obtain a graphite filter cake, and treating the graphite filter cake for 2 hours at the temperature of 500 ℃ under the protection of nitrogen.

5. The method for preparing a high-quality graphene battery according to claim 2, wherein the method comprises the following steps: in step S12, the graphite raw material pretreated in step S11, KOH and NaNO3 are placed in a reaction kettle, deionized water is added, and stirring is performed for 15 min; replacing gas in the reaction kettle with oxygen for 3 times under a sealed state, charging oxygen to 5MPa, raising the temperature to 500 ℃, and stirring for 40H; and cooling, mechanically stirring the reactants for 2 hours, carrying out solid-liquid separation, washing the solid product with 5% diluted hydrochloric acid, washing with deionized water to neutrality, and carrying out vacuum drying at 100 ℃ to obtain the graphene oxide solid.

6. The method for preparing a high-quality graphene battery according to claim 2, wherein the method comprises the following steps: in step S13, the graphene oxide treated in step S12 is prepared as an aqueous solution, the PH of the aqueous solution of graphene oxide is adjusted to 3 with HCL, and the aqueous solution of graphene is placed in an ultraviolet light device for reduction by irradiation for 40 hours.

7. The method for preparing a high-quality graphene battery according to claim 2, wherein the method comprises the following steps: in step S20, compounding graphene and a lithium titanate negative electrode material by preparing a titanium source dispersion solution from tetrabutyl titanate, graphene, P123, and tert-butyl alcohol, preparing a lithium source solution from lithium acetate dihydrate, deionized water, and tert-butyl alcohol, transferring the mixed titanium source dispersion solution to a microwave reactor, heating to reflux, adding the lithium source solution to react, cooling, removing the solvent, drying to obtain a graphene-based lithium titanate precursor, placing the obtained precursor in a tubular furnace, and calcining under the protection of N2 to obtain the graphene-lithium titanate composite material, wherein the graphene-lithium titanate composite material is a negative electrode slurry.

Technical Field

The invention relates to the technical field of battery manufacturing, in particular to a preparation method of a high-quality graphene battery.

Background

A lithium ion battery is a type of secondary battery that mainly operates by movement of lithium ions between a positive electrode and a negative electrode. During charging, lithium ions are extracted from the positive electrode and are inserted into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state; the opposite is true during discharge. The lithium ion battery has the obvious advantages of high energy density, high output voltage, long cycle life, small environmental pollution and the like, is widely applied to small digital electronic products, and has wide application prospect in the fields of hybrid electric vehicles, aerospace, diving and the like. Graphene is a hexagonal honeycomb structure formed by hybridizing carbon atoms based on sp2, is a two-dimensional crystal with the thickness of only one atomic layer, and has excellent performances in the aspects of electricity, optics, thermal mechanics and the like.

However, the rate performance and cycle performance of the current graphene battery in charge and discharge are still not completely satisfactory, so how to improve the rate performance and cycle performance is a difficult problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a preparation method of a high-quality graphene battery to solve the problems.

In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of a high-quality graphene battery comprises the following steps:

s10, preparing a graphene material: processing a graphite raw material step by step to obtain graphene powder;

s20, preparing anode slurry: compounding the graphene powder obtained in the step S10 with a lithium titanate negative electrode material by a sol-gel method, adding the prepared graphene powder into a conductive agent, and homogenizing by combining a binder to obtain negative electrode slurry;

s30, preparing positive electrode slurry: homogenizing a lithium manganate positive electrode material, a binder and a conductive agent to obtain positive electrode slurry;

s40, slurry coating: coating the negative electrode slurry prepared in the step S20 on a negative electrode sheet, and coating the positive electrode slurry prepared in the step S30 on a positive electrode sheet;

s50, assembling the battery: and (4) rolling and shearing the negative pole piece and the positive pole piece prepared in the step (S40), and assembling the negative pole piece and the positive pole piece into a battery frame.

As a modification of the present invention, in step S10, the graphene material preparation includes the following steps:

s11, pretreatment of graphite raw materials: stirring and mixing a graphite raw material and an organic solvent, filtering, and carrying out high-temperature treatment on a graphite filter cake obtained by filtering under the protection of inert gas;

s12, graphite oxidation treatment: adding the graphite raw material pretreated in the step S11 and an auxiliary oxidant into an alkali solution, placing the mixture into a closed space, introducing oxidation into the closed space to a certain pressure for reaction, and performing solid-liquid separation after the reaction is finished to obtain a solid phase, namely graphene oxide;

s13, reducing graphene oxide: preparing the graphene oxide prepared in the step S12 into a graphene oxide aqueous solution, adjusting the pH, and carrying out reduction reaction on the graphene oxide aqueous solution under the irradiation of ultraviolet light;

s14, post-processing: and (4) filtering and drying the aqueous solution obtained after the reduction in the step S13 to obtain graphene powder.

As an improvement of the present invention, in step S40, when the positive electrode tab and the negative electrode tab are subjected to slurry coating, empty foils are left on both the upper and lower sides of the positive electrode tab and the negative electrode tab.

As an improvement of the invention, in step S11, adding the graphite raw material and the organic solvent N-dimethylformamide solvent into a high-pressure reaction kettle, heating to 170 ℃, and stirring for 4 hours; and after cooling, taking out the graphite raw material, filtering to obtain a graphite filter cake, and treating the graphite filter cake for 2 hours at the temperature of 500 ℃ under the protection of nitrogen.

In step S12, the graphite raw material pretreated in step S11, KOH and NaNO3 are put into a reaction kettle, deionized water is added, and stirring is performed for 15 min; replacing gas in the reaction kettle with oxygen for 3 times under a sealed state, charging oxygen to 5MPa, raising the temperature to 500 ℃, and stirring for 40H; and cooling, mechanically stirring the reactants for 2 hours, carrying out solid-liquid separation, washing the solid product with 5% diluted hydrochloric acid, washing with deionized water to neutrality, and carrying out vacuum drying at 100 ℃ to obtain the graphene oxide solid.

In step S13, the graphene oxide treated in step S12 is prepared as an aqueous solution, the PH of the aqueous solution of graphene oxide is adjusted to 3 with HCL, and the aqueous solution of graphene is placed in an ultraviolet light device for reduction by irradiation for 40 hours.

In step S20, compounding graphene and a lithium titanate negative electrode material by preparing a titanium source dispersion solution from tetrabutyl titanate, graphene, P123, and tert-butyl alcohol, preparing a lithium source solution from lithium acetate dihydrate, deionized water, and tert-butyl alcohol, transferring the mixed titanium source dispersion solution to a microwave reactor, heating to reflux, adding the lithium source solution to react, cooling, removing the solvent, drying to obtain a graphene-based lithium titanate precursor, placing the obtained precursor in a tubular furnace, and calcining under the protection of N2 to obtain the graphene-lithium titanate composite material, wherein the graphene-lithium titanate composite material is the negative electrode slurry.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of illustration and description, and is in no way intended to limit the invention.

A preparation method of a high-quality graphene battery comprises the following steps:

s10, preparing a graphene material: processing a graphite raw material step by step to obtain graphene powder;

s20, preparing anode slurry: compounding the graphene powder obtained in the step S10 with a lithium titanate negative electrode material by a sol-gel method, adding the prepared graphene powder into a conductive agent, and homogenizing by combining a binder to obtain negative electrode slurry;

s30, preparing positive electrode slurry: homogenizing a lithium manganate positive electrode material, a binder and a conductive agent to obtain positive electrode slurry;

s40, slurry coating: coating the negative electrode slurry prepared in the step S20 on a negative electrode sheet, and coating the positive electrode slurry prepared in the step S30 on a positive electrode sheet;

s50, assembling the battery: and (4) rolling and shearing the negative pole piece and the positive pole piece prepared in the step (S40), and assembling the negative pole piece and the positive pole piece into a battery frame.

As an embodiment of the present invention, in step S10, the graphene material preparation includes the following steps:

s11, pretreatment of graphite raw materials: stirring and mixing a graphite raw material and an organic solvent, filtering, and carrying out high-temperature treatment on a graphite filter cake obtained by filtering under the protection of inert gas;

s12, graphite oxidation treatment: adding the graphite raw material pretreated in the step S11 and an auxiliary oxidant into an alkali solution, placing the mixture into a closed space, introducing oxidation into the closed space to a certain pressure for reaction, and performing solid-liquid separation after the reaction is finished to obtain a solid phase, namely graphene oxide;

s13, reducing graphene oxide: preparing the graphene oxide prepared in the step S12 into a graphene oxide aqueous solution, adjusting the pH, and carrying out reduction reaction on the graphene oxide aqueous solution under the irradiation of ultraviolet light;

s14, post-processing: and (4) filtering and drying the aqueous solution obtained after the reduction in the step S13 to obtain graphene powder.

In step S40, when the positive electrode tab and the negative electrode tab are coated with the slurry, empty foils are left on both the upper and lower sides of the positive electrode tab and the negative electrode tab.

As an embodiment of the present invention, in step S11, adding the graphite raw material and the organic solvent N-dimethylformamide solvent into a high pressure reaction kettle, raising the temperature to 170 ℃, and stirring for 4 hours; and after cooling, taking out the graphite raw material, filtering to obtain a graphite filter cake, and treating the graphite filter cake for 2 hours at the temperature of 500 ℃ under the protection of nitrogen.

As an embodiment of the present invention, in step S12, the graphite raw material pretreated in step S11, KOH and NaNO3 are placed in a reaction kettle, deionized water is added, and stirring is performed for 15 min; replacing gas in the reaction kettle with oxygen for 3 times under a sealed state, charging oxygen to 5MPa, raising the temperature to 500 ℃, and stirring for 40H; and cooling, mechanically stirring the reactants for 2 hours, carrying out solid-liquid separation, washing the solid product with 5% diluted hydrochloric acid, washing with deionized water to neutrality, and carrying out vacuum drying at 100 ℃ to obtain the graphene oxide solid.

In step S13, the graphene oxide treated in step S12 is prepared as an aqueous solution, the PH of the aqueous solution of graphene oxide is adjusted to 3 with HCL, and the aqueous solution of graphene is placed in an ultraviolet light device for reduction by irradiation for 40 hours.

As an embodiment of the present invention, in step S20, graphene and lithium titanate negative electrode material are compounded, where tetrabutyl titanate, graphene, P123, and tert-butyl alcohol are prepared into a titanium source dispersion solution, lithium acetate dihydrate, deionized water, and tert-butyl alcohol are prepared into a lithium source solution, the mixed titanium source dispersion solution is transferred to a microwave reactor and heated to reflux, a lithium source solution is added to react and cool, a solvent is removed and dried to obtain a graphene-based lithium titanate precursor, the obtained precursor is placed in a tubular furnace and calcined under the protection of N2 to obtain a graphene-lithium titanate composite material, and the graphene-lithium titanate composite material is negative electrode slurry.

The working principle and the beneficial effects of the technical scheme are as follows:

the specific implementation operation is as follows:

weighing 0.5g of 500-mesh graphite, weighing 10ml of N, N-dimethylformamide solvent, adding into a high-pressure reaction kettle, heating to 170 ℃, and stirring for 4H. After cooling, the graphite filter cake is taken out for filtration, and the graphite filter cake is treated for 2H at 500 ℃ under the protection of N2. 0.3g of pretreated graphite, 4Gkoh and 0.3g of NaNO3 are weighed and placed in a reaction kettle, 30ml of deionized water is added, and stirring is carried out for 15 mins. Sealing, replacing gas in the reaction kettle with oxygen for 3 times, introducing oxygen to 5MPa, heating to 500 deg.C, and stirring for 40H. And cooling, mechanically stirring the reactants for 2 hours, carrying out solid-liquid separation, washing the solid product with 5% diluted hydrochloric acid, washing with deionized water to neutrality, and carrying out vacuum drying at 100 ℃ to obtain the graphene oxide solid. Weighing 0.1g of graphene oxide to prepare an aqueous solution, adjusting the pH value of the aqueous solution of graphene oxide to 3 by using HCL, measuring 3ML of the aqueous solution of graphene into a 5ML small glass bottle, horizontally placing the small glass bottle into an ultraviolet analyzer, adjusting the wavelength to 245nm and carrying out irradiation reduction for 40 hours at a position 5cm away from a fluorescent lamp. And finally, filtering the graphene aqueous solution reduced by the reaction, and drying in vacuum to obtain high-quality graphene powder.

Preparing a graphene battery: performing a homogenate procedure of slurry required by coating a battery positive pole piece through a lithium manganate positive pole, a binder and a conductive agent, and preparing coating preparation after preparing the slurry; then compounding the prepared graphene and a lithium titanate negative electrode material, adding the graphene into a conductive agent, and combining a binder to perform a slurry homogenizing process of coating slurry required by a battery negative electrode plate, wherein the prepared slurry is prepared for coating; compounding graphene and a lithium titanate negative electrode material, namely preparing titanium source dispersion liquid from tetrabutyl titanate, graphene, P123 and tert-butyl alcohol, preparing lithium source solution from lithium acetate dihydrate, deionized water and tert-butyl alcohol, transferring the mixed titanium source dispersion liquid into a microwave reactor, heating to reflux, adding the lithium source solution, reacting for a certain time, cooling, removing a solvent, and drying to obtain a graphene-based lithium titanate precursor. Placing the obtained precursor in a tubular furnace, and calcining under the protection of N2 to obtain the graphene/lithium titanate composite material; and performing positive and negative electrode coating procedures on the prepared slurry, reserving empty foils on two sides of the pole piece, performing rolling and shearing procedures on the pole piece, and finally assembling to obtain the graphene battery.

The invention provides a preparation method of a high-quality graphene battery, wherein graphene is a hexagonal honeycomb structure formed by hybridizing carbon atoms based on sp2, is a two-dimensional crystal with the thickness of only one atomic layer, and has excellent performances in the aspects of electricity, optics, thermal mechanics and the like. The lithium titanate battery cathode has poor conductivity, but the graphene and lithium titanate composite material can effectively improve the active substance ratio of the battery material, and more importantly, the rate performance can be improved while the cycle performance can be improved.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.