CN117154021A - Three-dimensional lithium metal negative electrode and preparation method thereof, lithium-ion battery - Google Patents

Abstract

A three-dimensional lithium metal negative electrode, a preparation method thereof and a lithium ion battery belong to the technical field of lithium batteries and overcome the defect of poor cycle performance of the lithium metal negative electrode in the prior art. The preparation method of the three-dimensional lithium metal anode comprises the following steps: step 1, loading active metal oxide and carbon on a carbon support layer to prepare an active metal oxide-C/carbon support layer; step 2, growing a conductive polymer in situ on the active metal oxide-C/carbon support layer to prepare the conductive polymer-active metal oxide-C/carbon support layer; and 3, loading metal lithium on the conductive polymer-active metal oxide-C/carbon support layer to prepare the three-dimensional lithium metal anode. The three-dimensional metal lithium cathode can improve the safety and the service life of a battery.

Description

A three-dimensional lithium metal negative electrode and preparation method thereof, and lithium ion battery

Technical Field

The present invention belongs to the technical field of lithium batteries, and specifically relates to a three-dimensional lithium metal negative electrode and a preparation method thereof, and a lithium ion battery.

Background Art

In recent years, with the continuous growth of energy demand and the intensification of environmental crisis, high-performance energy storage devices and devices have received extensive attention. Compared with other devices, lithium-ion batteries are suitable for various new energy products on the market, such as new energy vehicles and electronic devices. So far, traditional graphite materials have been widely used as commercial anode materials for lithium-ion batteries. However, the theoretical capacity of graphite anode materials in most lithium-ion batteries is only 372mAh g ^-1 , which has slowed the development of commercial lithium-ion batteries in recent years. Metallic lithium has a higher theoretical specific capacity (3860mAh g ^- 1) and the lowest reduction potential (-3.04V vs. standard hydrogen electrode), which makes the energy density of lithium-ion batteries potentially reach 500Wh kg ^-1 , making it an ideal anode material for lithium-ion batteries. However, metal lithium anodes will show two problems during the cycle process: ① uncontrolled lithium dendrite growth and ② volume expansion during the cycle process. These two problems seriously limit the practical application of lithium metal as anode material in lithium-ion batteries.

In order to solve the above problems, researchers have adopted various strategies to optimize the performance of lithium metal anodes and promote their commercial application. For example, new electrolyte additives are used to enhance the mechanical strength of the formed SEI or high modulus artificial SEI and solid electrolytes are used to inhibit the growth of lithium dendrites. Although these methods can stabilize the electrolyte/anode interface, they cannot provide additional space for the deposition of lithium metal. This makes the problem of volume change still exist, which is not conducive to the long cycle performance of the battery. The commercial application of lithium-ion batteries with graphite as the anode is due to the fact that lithium ions can be stably embedded/extracted in the interlayer structure of graphite. Based on this idea, if lithium can be stably deposited/exfoliated in a host structure during the charge and discharge cycle of the metal lithium anode, it is expected to alleviate the problems of lithium dendrites and volume expansion in the lithium anode. Constructing a three-dimensional framework with sufficient space to accommodate the deposited lithium metal is a strategy. Moreover, based on the "Sand's time" theory, a three-dimensional framework with a large specific surface area can effectively reduce the local current density, so it can both inhibit the growth of lithium dendrites and stabilize the volume change.

Three-dimensional carbon fiber cloth is considered to be a lithium negative electrode skeleton material with great application value due to its light weight, ultra-high conductivity, interface modifiability, low cost and commercial availability. However, the lithium-repellent nature of the carbon material interface increases the nucleation overpotential and deposition resistance of metallic lithium on its surface. Especially at higher current densities, the lithium nucleation sites on the lithium-repellent surface tend to be isolated and distributed, and subsequent lithium ions tend to preferentially deposit on these nucleation sites, resulting in uneven deposition of lithium metal in the porous lithium-repellent carbon cloth fiber skeleton. After long-term cycling, the problem of negative electrode lithium dendrite growth is inevitable.

Summary of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the defect of poor cycle performance of metal lithium negative electrode in the prior art, thereby providing a three-dimensional lithium metal negative electrode and a preparation method thereof, and a lithium ion battery.

To this end, the present invention provides the following technical solutions.

In a first aspect, the present invention provides a method for preparing a three-dimensional lithium metal anode, comprising the following steps:

Step 1, loading active metal oxide and carbon on a carbon support layer to prepare an active metal oxide-C/carbon support layer;

Step 2, in-situ growing a conductive polymer on the active metal oxide-C/carbon support layer to prepare a conductive polymer-active metal oxide-C/carbon support layer;

Step 3: Loading metallic lithium onto the conductive polymer-active metal oxide-C/carbon support layer to obtain the three-dimensional lithium metal negative electrode.

The carbon support layer is a three-dimensional structure.

Furthermore, at least one of the following conditions is met:

(1) The active metal oxide includes at least one of zinc oxide, tin oxide and copper oxide;

(2) The conductive polymer includes at least one of polyaniline, polypyrrole and polythiophene.

Furthermore, the step 1 comprises:

Step 101, dissolving 8-hydroxyquinoline in a mixed solvent of a polar solvent and a non-polar solvent, and then adding a carbon support layer;

Step 102, adding the active metal salt solution to the solution of step 101, heating to react, and then taking out the carbon support layer after the reaction;

Step 103, washing and drying the carbon support layer after the reaction to obtain an 8-hydroxyquinoline-active metal/carbon support layer;

Step 104: calcining the 8-hydroxyquinoline-active metal/carbon support layer to obtain an active metal oxide-C/carbon support layer.

Furthermore, step 1 satisfies at least one of the following conditions:

(1) In the step 101, the concentration of 8-hydroxyquinoline after being dissolved in the mixed solvent is 10 mg/mL-100 mg/mL;

(2) In step 102, the active metal salt includes at least one of zinc sulfate, zinc chloride, zinc nitrate, tin chloride, copper sulfate, copper nitrate, and copper chloride;

(3) In step 102, the concentration of the active metal salt solution is 8 mg/mL-100 mg/mL;

The volume ratio of the active metal salt solution to the solution in step 101 is 1:2 to 5:1;

(4) In step 102, the heating reaction temperature is 40-80° C. and the reaction time is 1-10 hours;

(5) In step 103, the drying is: drying in a vacuum drying oven at 40-100° C. for 1-24 hours;

(6) In step 104, the calcination condition is heat treatment at 300-500°C for 1-5 hours.

Furthermore, in step 101, the volume ratio of the polar solvent to the non-polar solvent in the mixed solvent is 1:1 to 10:1;

Optionally, the polar solvent includes at least one of methanol, ethanol and water;

Optionally, the non-polar solvent includes at least one of benzene and toluene.

In a possible design, the conductive polymer is polyaniline, and step 2 comprises:

Step 201, adding active metal oxide-C/carbon support layer and aniline into an acidic aqueous solution, and stirring at 0-7°C;

Step 202, adding an aqueous solution of ammonium persulfate to the solution of step 201, and continuing the reaction at 0-7°C for 1-24 hours;

Step 203: Wash and dry the product of step 202 to obtain a polyaniline-active metal oxide-C/carbon support layer.

Furthermore, step 2 satisfies at least one of the following conditions:

(1) In step 201, the concentration of the acidic aqueous solution is 0.5 to 3 mol/L;

Optionally, the acidic aqueous solution is a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution or a nitric acid aqueous solution;

(2) In step 201, after adding aniline, the concentration of aniline in the acidic aqueous solution is 0.5 mol/L-10 mol/L;

(3) In step 202, the concentration of the ammonium persulfate aqueous solution is 0.4 mol/L-5 mol/L;

The volume ratio of the ammonium persulfate aqueous solution to the solution in step 201 is 1:2 to 5:1;

(4) The drying in step 203 is performed in a vacuum drying oven at 40-100° C. for 1-24 hours.

In one possible design, the conductive polymer is polypyrrole, and step 2 comprises:

Step 201', mixing a surfactant, pyrrole and water to obtain a solution A, placing an active metal oxide-C/carbon support layer in the solution A, and stirring at 0-7°C;

Step 202', adding an aqueous solution of ferric chloride to solution A, and continuing the reaction at 0-7°C for 1-24 hours;

Step 203', washing and drying the product of step 202' to obtain a polypyrrole-active metal oxide-C/carbon support layer.

Furthermore, step 2 satisfies at least one of the following conditions:

(1) In solution A, the concentration of surfactant is 0.05-0.5 mol/L, and the concentration of pyrrole is 0.5-2 mol/L;

(2) The surfactant is sodium dodecylbenzene sulfonate;

(3) the concentration of the ferric chloride aqueous solution is 0.02-0.2 mol/L;

The volume ratio of the ferric chloride aqueous solution to solution A is 1:2 to 5:1.

In one possible design, the conductive polymer is polythiophene, and step 2 comprises:

Step 201", adding ferric chloride to a trichlorotoluene solution to prepare a solution B, placing an active metal oxide-C/carbon support layer in the solution B, and stirring at 0-7°C;

Step 202", adding thiophene to solution B, reacting at 0-7°C for 24h;

Step 203 ”, washing and drying the product of step 202 ” to obtain a polythiophene-active metal oxide-C/carbon support layer.

Furthermore, step 2 satisfies at least one of the following conditions:

(1) In step 201", the concentration of ferric chloride in solution B is 0.5-1 mol/L;

(2) In step 202", the mass ratio of thiophene added to ferric chloride is 1:(4-6).

Furthermore, the step 3 comprises: rolling the metal lithium foil onto the conductive polymer-active metal oxide-C/carbon support layer.

Furthermore, the step 3 comprises: using the metal lithium sheet as the working electrode and the counter electrode, and electro-depositing the metal lithium onto the conductive polymer-active metal oxide-C/carbon support layer.

In a second aspect, the present invention provides a three-dimensional lithium metal negative electrode prepared according to the above method.

In a third aspect, the present invention provides a lithium-ion battery comprising the above-mentioned three-dimensional lithium metal negative electrode.

Furthermore, before step 1, the carbon support layer is pretreated, and the pretreatment includes:

A. Place the carbon support layer in a mixed solution of concentrated nitric acid and concentrated sulfuric acid at a temperature of 50-80° C. for 1-6 hours. After the reaction is completed, wash the carbon support layer with deionized water until the washed water is neutral, thereby obtaining a hydrophilic carbon support layer;

B. The hydrophilic carbon support layer is ultrasonically treated in acetone, anhydrous ethanol and deionized water for 1-20 minutes, and repeated 2-10 times. Then, the hydrophilic carbon support layer is taken out and placed in a vacuum drying oven at 40-100° C. for 1-24 hours.

The technical solution of the present invention has the following advantages:

1. The preparation method of the three-dimensional lithium metal negative electrode of the present invention comprises the following steps: step 1, loading active metal oxide and carbon on a carbon support layer to obtain an active metal oxide-C/carbon support layer; step 2, in situ growing a conductive polymer on the active metal oxide-C/carbon support layer to obtain a conductive polymer-active metal oxide-C/carbon support layer; step 3, loading metallic lithium onto the conductive polymer-active metal oxide-C/carbon support layer to obtain the three-dimensional lithium metal negative electrode.

The present invention constructs a uniform nanostructure with lithium-philic properties on the surface of a three-dimensional framework, which can not only reduce the local current density by utilizing the large specific surface area, but also induce the uniform nucleation and deposition of lithium metal with the help of lithium-philic materials, thereby achieving the purpose of improving the performance of the lithium metal negative electrode.

The present invention adopts a carbon support layer with a three-dimensional structure as a substrate material, and finally forms a conductive polymer-active metal oxide-C/carbon support layer by growing active metal oxide-C and conductive polymer on its surface. The three-dimensional carbon support layer can effectively inhibit the growth of lithium dendrites and enhance mechanical flexibility. The surface-modified lithium-philic active metal oxide-C can provide a driving force for lithium to enter the host (conductive polymer-ZnO-C/carbon support layer), and the addition of conductive polymer can improve the contact between lithium and solid electrolyte. The three-dimensional metal lithium negative electrode can be used not only in liquid lithium batteries but also in high-energy-density lithium solid-state batteries, effectively reducing local current density, inhibiting the growth of lithium dendrites, and improving battery safety and life.

The present invention has excellent flexibility, ionic conductivity and electrical conductivity under the synergistic effect of conductive polymer, carbon support layer and ZnO, and can effectively improve the migration and transmission of lithium ions; ZnO has strong lithium affinity and can significantly improve the lithium wettability of carbon cloth; and the space of the carbon support layer can not only pre-store lithium, but also play a role in buffering lithium expansion, so that lithium ions are evenly distributed, thereby inhibiting the growth of lithium dendrites and improving the electrochemical performance of lithium batteries. Conductive polymers can further buffer the volume expansion of lithium to a certain extent, and at the same time can improve the contact between lithium and solid electrolytes.

DETAILED DESCRIPTION

The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be purchased commercially.

The carbon cloth in the examples and comparative examples was purchased from Shanghai Hesen Electric Co., Ltd.

Example 1

This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) The ZnO-C/carbon obtained in step (7) was placed in a hydrochloric acid aqueous solution, and then 4.65 g of aniline was dispersed in 50 ml of a hydrochloric acid aqueous solution (hydrochloric acid concentration was 1 mol/L), followed by stirring at 0°C for 2 h.

(9) Dissolve 5.7 g of ammonium persulfate in 50 ml of deionized water.

(10) Slowly add the solution in step (9) to step (8). After complete addition, continue the reaction at 0°C for 24 hours.

(11) The product obtained in step (10) was washed with anhydrous ethanol and deionized water, and then dried in a vacuum drying oven at 50° C. for 24 hours to obtain a polyaniline-ZnO-C/carbon cloth composite material.

(12) A 0.05 mm thick lithium foil was slowly rolled onto the polyaniline-ZnO-C/carbon cloth to obtain a Li-polyaniline-ZnO-C/carbon cloth composite lithium negative electrode.

Example 2

This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of Embodiment 1, except that:

(12) Using polyaniline-ZnO-C/carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is electrodeposited onto polyaniline-ZnO-C/carbon cloth to obtain a Li-polyaniline-ZnO-C/carbon cloth composite lithium negative electrode.

Example 3

This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) The ZnO-C/carbon obtained in step (7) was placed in 50 ml of deionized water containing 1.74 g of sodium dodecylbenzene sulfonate and 3.35 g of pyrrole, and then stirred at a low temperature of 5°C for 2 h.

(9) Dissolve 0.5 g of ferric chloride in 50 ml of deionized water.

(10) Slowly add the solution in step (9) to step (8). After complete addition, continue the reaction at a low temperature of 5°C for 24 hours.

(11) The product obtained in step (10) was washed with anhydrous ethanol and deionized water, and then dried in a vacuum drying oven at 50° C. for 24 hours to obtain a polypyrrole-ZnO-C/carbon cloth composite material.

(12) A 0.05 mm thick lithium foil was slowly rolled onto the polypyrrole-ZnO-C/carbon cloth to obtain a Li-polypyrrole-ZnO-C/carbon cloth composite lithium negative electrode.

Example 4

This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of Embodiment 3, except that:

(12) Using polypyrrole-ZnO-C/carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is electrodeposited onto polypyrrole-ZnO-C/carbon cloth to obtain a Li-polypyrrole-ZnO-C/carbon cloth composite lithium anode.

Example 5

This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) Dissolve 5 g of ferric chloride in 50 ml of chloroform, and place the ZnO-C/carbon obtained in step (7) in the above solution, and stir at low temperature of 0°C for 2 h.

(9) Slowly add 1 g of thiophene liquid into (8) and react at low temperature of 0°C for 24 hours.

(10) The product obtained in step (9) was washed with anhydrous ethanol and deionized water, and then dried in a vacuum drying oven at 50° C. for 24 hours to obtain a polythiophene-ZnO-C/carbon cloth composite material.

(11) A 0.05 mm thick lithium foil was slowly rolled onto the polythiophene-ZnO-C/carbon cloth to obtain a Li-polythiophene-ZnO-C/carbon cloth composite lithium negative electrode.

Example 6

This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of Embodiment 5, except that:

(11) Using polythiophene-ZnO-C/carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is deposited on polythiophene-ZnO-C/carbon cloth to obtain the Li-polythiophene-ZnO-C/carbon cloth composite lithium anode.

Example 7

This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 3 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solution of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1.5 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) The ZnO-C/carbon obtained in step (7) was placed in a hydrochloric acid aqueous solution, and then 7 g of aniline was dispersed in 50 ml of a hydrochloric acid aqueous solution (hydrochloric acid concentration was 1 mol/L), and then stirred at a low temperature of 5°C for 2 h.

(9) Dissolve 8.6 g of ammonium persulfate in 50 ml of deionized water.

(10) Slowly add the solution in step (9) to step (8). After complete addition, continue the reaction at a low temperature of 5°C for 24 hours.

(11) The product obtained in step (10) was washed with anhydrous ethanol and deionized water, and then dried in a vacuum drying oven at 50° C. for 24 hours to obtain a polyaniline-ZnO-C/carbon cloth composite material.

(12) A 0.05 mm thick lithium foil was slowly rolled onto the polyaniline-ZnO-C/carbon cloth to obtain a Li-polyaniline-ZnO-C/carbon cloth composite lithium negative electrode.

Comparative Example 1

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) Slowly roll a 0.05 mm thick lithium foil onto a hydrophilic carbon cloth to obtain a Li/carbon cloth composite lithium negative electrode.

Comparative Example 2

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as comparative example 1, except that:

(3) Using hydrophilic carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is deposited on the hydrophilic carbon cloth to obtain a Li-carbon cloth composite lithium negative electrode.

Comparative Example 3

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) A 0.05 mm thick lithium foil is slowly rolled onto the ZnO-C/carbon cloth to obtain a Li/ZnO-C/carbon cloth composite lithium negative electrode.

Comparative Example 4

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as comparative example 3, except that:

(8) Using ZnO-C/carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is deposited on the ZnO-C/carbon cloth to obtain a Li-ZnO-C/carbon cloth composite lithium negative electrode.

Comparative Example 5

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) Commercial polyaniline, polyvinylidene fluoride, and N-methylpyrrolidone were ground into a mass ratio of 8:1:1 and then coated onto ZnO-C/carbon cloth to obtain polyaniline-ZnO-C/carbon cloth.

(9) Slowly roll 0.05 mm lithium metal foil onto the polyaniline-ZnO-C/carbon cloth to obtain the Li-polyaniline-ZnO-C/carbon cloth composite lithium negative electrode.

Comparative Example 6

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as comparative example 5, except that:

(9) Using polyaniline-ZnO-C/carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is electrodeposited onto polyaniline-ZnO-C/carbon cloth to obtain a Li-polyaniline-ZnO-C/carbon cloth composite lithium negative electrode.

Comparative Example 7

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) Commercial polypyrrole, polyvinylidene fluoride, and N-methylpyrrolidone were ground into a mass ratio of 8:1:1 and then coated onto ZnO-C/carbon cloth to obtain polypyrrole-ZnO-C/carbon cloth.

(9) A 0.05 mm thick lithium metal foil is slowly rolled onto the polypyrrole-ZnO-C/carbon cloth to obtain a Li-polypyrrole-ZnO-C/carbon cloth composite lithium negative electrode.

(10) The composite lithium negative electrode and the battery-grade copper sheet form a Li-Cu half-cell with a current density of 0.25 mA/cm ² and a capacity parameter of 0.5 mAh/cm ² . The test results are shown in Table 1.

Comparative Example 8

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as comparative example 7, except that:

(9) Using polypyrrole-ZnO-C/carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is deposited on the polypyrrole-ZnO-C/carbon cloth to obtain a Li-polypyrrole-ZnO-C/carbon cloth composite lithium negative electrode.

Comparative Example 9

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

(1) First, a 5cm*5cm carbon cloth was treated by placing the carbon cloth in a mixed solution of concentrated nitric acid and concentrated sulfuric acid. The mixed solution was prepared by mixing concentrated nitric acid (16mol/L) and concentrated sulfuric acid (18.4mol/L) in a volume ratio of 3:1, and reacting at 80°C for 5 hours. After the reaction, the carbon cloth was repeatedly washed with deionized water until the washed water was neutral, thus obtaining a hydrophilic carbon cloth.

(2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, respectively, for 5 times, and then taken out and dried in a vacuum drying oven at 50° C. for 24 hours.

(3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, wherein the volume ratio of anhydrous ethanol to benzene was 4:1, and then the carbon cloth was added.

(4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

(5) The solution in (4) was added to the solution in (3), and the mixture was reacted at 80°C for 5 hours.

(6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water respectively, which is repeated for 3 times, and then placed in a vacuum drying oven at 80° C. for 12 hours to obtain an 8-hydroxyquinoline-zinc/carbon cloth composite.

(7) The 8-hydroxyquinoline-zinc/carbon cloth composite was placed in a muffle furnace and heat treated at 400°C for 2 hours to obtain ZnO-C/carbon cloth.

(8) Commercial polythiophene, polyvinylidene fluoride, and N-methylpyrrolidone are ground into a mass ratio of 8:1:1 and then coated onto ZnO-C/carbon cloth to obtain polythiophene-ZnO-C/carbon cloth.

(9) A 0.05 mm thick lithium foil is slowly rolled onto the polythiophene-ZnO-C/carbon cloth to obtain a Li-polythiophene-ZnO-C/carbon cloth composite lithium negative electrode.

Comparative Example 10

This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as comparative example 9, except that:

(9) Using polythiophene-ZnO-C/carbon cloth as the working electrode and metal lithium sheet as the working electrode and counter electrode, metal lithium is deposited on the polythiophene-ZnO-C/carbon cloth to obtain a Li-polythiophene-ZnO-C/carbon cloth composite lithium negative electrode.

Test example

The three-dimensional lithium metal negative electrodes prepared in the embodiment and comparative example were respectively combined with battery-grade copper sheets to form Li-Cu half-cells. The test current density was 0.25 mA/cm ² , and the capacity parameter was 0.5 mAh/cm ² . The test results are shown in Table 1.

Table 1 Test results of Li-Cu half-cells prepared in Example

Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims (15)

1. A method for preparing a three-dimensional lithium metal negative electrode, which is characterized by comprising the following steps: Step 1. Load the active metal oxide and carbon on the carbon support layer to prepare the active metal oxide-C/carbon support layer; Step 2: Grow the conductive polymer in situ on the active metal oxide-C/carbon support layer to prepare the conductive polymer-active metal oxide-C/carbon support layer; Step 3: Load metallic lithium onto the conductive polymer-active metal oxide-C/carbon support layer to prepare the three-dimensional lithium metal negative electrode. 2. The method for preparing a three-dimensional lithium metal negative electrode according to claim 1, characterized in that at least one of the following conditions is met: (1) The active metal oxide includes at least one of zinc oxide, tin oxide, and copper oxide; (2) The conductive polymer includes at least one of polyaniline, polypyrrole, and polythiophene. 3. The method for preparing a three-dimensional lithium metal negative electrode according to claim 1 or 2, characterized in that said step 1 includes: Step 101. Dissolve 8-hydroxyquinoline in a mixed solvent of polar solvent and non-polar solvent, and then add a carbon support layer; Step 102: Add the active metal salt solution to the solution in step 101, heat the reaction, and then take out the reacted carbon support layer; Step 103: Clean and dry the reacted carbon support layer to obtain an 8-hydroxyquinoline-active metal/carbon support layer; Step 104: Calculate the 8-hydroxyquinoline-active metal/carbon support layer to obtain the active metal oxide-C/carbon support layer. 4. The method for preparing a three-dimensional lithium metal negative electrode according to claim 3, characterized in that step 1 satisfies at least one of the following conditions: (1) In step 101, the concentration of 8-hydroxyquinoline dissolved in the mixed solvent is 10 mg/mL-100 mg/mL; (2) In step 102, the active metal salt includes at least one of zinc sulfate, zinc chloride, zinc nitrate, tin chloride, copper sulfate, copper nitrate, and copper chloride; (3) In step 102, the concentration of the active metal salt solution is 8 mg/mL-100 mg/mL; The volume ratio of the active metal salt solution to the solution in step 101 is 1:2 to 5:1; (4) In step 102, the temperature of the heating reaction is 40-80°C, and the reaction is carried out for 1-10 hours; (5) In step 103, the drying is: drying in a vacuum drying oven at 40-100°C for 1-24 hours; (6) In step 104, the calcination condition is heat treatment at 300-500°C for 1-5 hours. 5. The method for preparing a three-dimensional lithium metal negative electrode according to claim 3, characterized in that in step 101, in the mixed solvent, the volume ratio of the polar solvent to the non-polar solvent is 1:1 to 10:1. ; Optionally, the polar solvent includes at least one of methanol, ethanol, and water; Optionally, the non-polar solvent includes at least one of benzene and toluene. 6. The method for preparing a three-dimensional lithium metal negative electrode according to any one of claims 1 to 5, wherein the conductive polymer is polyaniline, and the step 2 includes: Step 201: Add the active metal oxide-C/carbon support layer and aniline into the acidic aqueous solution, and stir at 0 to 7°C; Step 202: Add the ammonium persulfate aqueous solution to the solution in step 201, and continue the reaction at 0-7°C for 1-24 hours; Step 203: Clean and dry the product of step 202 to obtain a polyaniline-active metal oxide-C/carbon support layer. 7. The method for preparing a three-dimensional lithium metal negative electrode according to claim 6, characterized in that step 2 satisfies at least one of the following conditions: (1) In step 201, the concentration of the acidic aqueous solution is 0.5~3mol/L; Optionally, the acidic aqueous solution is a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution or a nitric acid aqueous solution; (2) In step 201, the concentration of aniline in the acidic aqueous solution after adding aniline is 0.5mol/L-10mol/L; (3) In step 202, the concentration of the ammonium persulfate aqueous solution is 0.4mol/L-5mol/L; The volume ratio of the ammonium persulfate aqueous solution to the solution in step 201 is 1:2 to 5:1; (4) The drying in step 203 is drying in a vacuum drying oven at 40-100°C for 1-24 hours. 8. The method for preparing a three-dimensional lithium metal negative electrode according to any one of claims 1 to 5, wherein the conductive polymer is polypyrrole, and the step 2 includes: Step 201', mix surfactant, pyrrole and water to obtain solution A, place the active metal oxide-C/carbon support layer in solution A, and stir at 0 to 7°C; Step 202', add the ferric chloride aqueous solution into solution A, and continue the reaction at 0 to 7°C for 1 to 24 hours; Step 203': Clean and dry the product of step 202' to obtain a polypyrrole-active metal oxide-C/carbon support layer. 9. The method for preparing a three-dimensional lithium metal negative electrode according to claim 8, characterized in that step 2 satisfies at least one of the following conditions: (1) In solution A, the concentration of surfactant is 0.05~0.5mol/L, and the concentration of pyrrole is 0.5~2mol/L; (2) The surfactant is sodium dodecylbenzene sulfonate; (3) The concentration of ferric chloride aqueous solution is 0.02~0.2mol/L; The volume ratio of ferric chloride aqueous solution to solution A is 1:2 to 5:1. 10. The method for preparing a three-dimensional lithium metal negative electrode according to any one of claims 1 to 5, wherein the conductive polymer is polythiophene, and the step 2 includes: Step 201", add ferric chloride to the trichlorotoluene solution to prepare solution B, place the active metal oxide-C/carbon support layer in solution B, and stir at 0-7°C; Step 202": Add thiophene to solution B and react at 0-7°C for 24 hours; Step 203": Clean and dry the product of step 202" to obtain a polythiophene-active metal oxide-C/carbon support layer. 11. The method for preparing a three-dimensional lithium metal negative electrode according to claim 10, characterized in that step 2 satisfies at least one of the following conditions: (1) In step 201", the concentration of ferric chloride in solution B is 0.5~1mol/L; (2) In step 202", the mass ratio of the added amount of thiophene to ferric chloride is 1: (4-6). 12. The method for preparing a three-dimensional lithium metal negative electrode according to any one of claims 1 to 11, characterized in that step 3 includes: rolling the metal lithium foil to the conductive polymer-active metal oxide-C/ on the carbon support layer. 13. The method for preparing a three-dimensional lithium metal negative electrode according to any one of claims 1 to 11, characterized in that step 3 includes: using metal lithium sheets as working electrodes and counter electrodes, electrodepositing metal lithium to conductive polymerization material-active metal oxide-C/carbon support layer. 14. A three-dimensional lithium metal negative electrode prepared according to the method of any one of claims 1-13. 15. A lithium ion battery comprising the three-dimensional lithium metal negative electrode of claim 14.