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

Abstract

A three-dimensional lithium metal anode, a preparation method thereof, and a lithium-ion battery belong to the field of lithium battery technology and overcome the poor cycling performance of metal lithium anodes in the prior art. The preparation method of the three-dimensional lithium metal anode of the present invention comprises the following steps: Step 1, loading an active metal oxide and carbon on a carbon support layer to produce 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 produce 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 produce the three-dimensional lithium metal anode. The three-dimensional lithium metal anode of the present invention can improve battery safety and lifespan.

Description

Technical Field

[0001] 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

[0002] In recent years, with the continuous growth of energy demand and the intensification of environmental crises, high-performance energy storage devices and devices have received widespread attention. Compared with other devices, lithium-ion batteries are suitable for a variety of new energy products on the market, such as new energy vehicles and electronic devices. To date, 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 372 mAh g -1 As a result, the development of commercial lithium-ion batteries has slowed down in recent years. However, metallic lithium has a higher theoretical specific capacity (3860mAh g -1 ) and the lowest reduction potential (-3.04 V vs. standard hydrogen electrode), making it possible for the energy density of lithium-ion batteries to reach 500Wh kg -1 , is an ideal negative electrode material for lithium-ion batteries. However, metallic lithium anodes exhibit two problems during cycling: ① uncontrolled lithium dendrite growth and ② volume expansion during cycling. These two problems severely limit the practical application of lithium metal as a negative electrode material in lithium-ion batteries.

[0003] To address these issues, researchers have adopted various strategies to optimize the performance of lithium metal anodes and promote their commercial application. For example, novel electrolyte additives are used to enhance the mechanical strength of the formed SEI, or high-modulus artificial SEIs and solid electrolytes are employed to inhibit the growth of lithium dendrites. While these approaches can stabilize the electrolyte / anode interface, they fail to provide additional space for lithium metal deposition. This leaves the volume change issue unaffected, hindering the battery's long-cycle performance. The commercialization of lithium-ion batteries using graphite as anodes is due to the stable intercalation and deintercalation of lithium ions within the graphite interlayer structure. Based on this idea, if lithium can be stably deposited and deintercalated within a host structure during the charge-discharge cycle of the lithium metal anode, the problems of lithium dendrites and volume expansion can be alleviated. One strategy is to construct a three-dimensional framework with sufficient space to accommodate the deposited lithium metal. Furthermore, based on the "Sand's time" theory, a three-dimensional framework with a large specific surface area can effectively reduce the local current density, thereby suppressing lithium dendrite growth and stabilizing volume change.

[0004] Three-dimensional carbon fiber cloth is considered a highly valuable lithium anode skeleton material due to its light weight, ultra-high conductivity, interface modifiability, low cost, and commercial availability. However, the lithium-phobic nature of the carbon material interface increases the nucleation overpotential and deposition resistance of metallic lithium on its surface. Especially at high current densities, the lithium nucleation sites on the lithium-phobic surface tend to be isolated, and subsequent lithium ions tend to preferentially deposit on these nucleation sites, resulting in uneven deposition of lithium metal within the porous lithium-phobic carbon cloth fiber skeleton. This makes the growth of lithium dendrites at the negative electrode inevitable after long-term cycling. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect of poor cycle performance of metallic lithium negative electrodes in the prior art, thereby providing a three-dimensional lithium metal negative electrode and a preparation method thereof, and a lithium ion battery.

[0006] To this end, the present invention provides the following technical solutions.

[0007] In a first aspect, the present invention provides a method for preparing a three-dimensional lithium metal anode, comprising the following steps:

[0008] Step 1: loading active metal oxide and carbon on a carbon support layer to prepare an active metal oxide-C / carbon support layer;

[0009] 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;

[0010] Step 3: Loading metallic lithium onto the conductive polymer-active metal oxide-C / carbon support layer to prepare the three-dimensional lithium metal negative electrode.

[0011] The carbon support layer has a three-dimensional structure.

[0012] Furthermore, at least one of the following conditions is met:

[0013] (1) The active metal oxide includes at least one of zinc oxide, tin oxide, and copper oxide;

[0014] (2) The conductive polymer includes at least one of polyaniline, polypyrrole, and polythiophene.

[0015] Furthermore, the step 1 includes:

[0016] 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;

[0017] Step 102: adding the active metal salt solution to the solution of step 101, heating to react, and then removing the carbon support layer after the reaction;

[0018] Step 103: Cleaning and drying the carbon support layer after the reaction to obtain an 8-hydroxyquinoline-active metal / carbon support layer;

[0019] Step 104 , calcining the 8-hydroxyquinoline-active metal / carbon support layer to obtain an active metal oxide-C / carbon support layer.

[0020] Furthermore, step 1 satisfies at least one of the following conditions:

[0021] (1) In step 101, the concentration of 8-hydroxyquinoline after being dissolved in the mixed solvent is 10 mg / mL to 100 mg / mL;

[0022] (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;

[0023] (3) In step 102, the concentration of the active metal salt solution is 8 mg / mL-100 mg / mL;

[0024] The volume ratio of the active metal salt solution to the solution in step 101 is 1:2 to 5:1;

[0025] (4) In step 102, the heating reaction temperature is 40-80° C. and the reaction time is 1-10 hours;

[0026] (5) In step 103, the drying step is: drying in a vacuum drying oven at 40-100° C. for 1-24 hours;

[0027] (6) In step 104, the calcination condition is heat treatment at 300-500°C for 1-5 hours.

[0028] 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;

[0029] Optionally, the polar solvent includes at least one of methanol, ethanol, and water;

[0030] Optionally, the non-polar solvent includes at least one of benzene and toluene.

[0031] In one possible design, the conductive polymer is polyaniline, and step 2 includes:

[0032] Step 201: adding an active metal oxide-C / carbon support layer and aniline to an acidic aqueous solution and stirring at 0-7° C.;

[0033] 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;

[0034] Step 203: Wash and dry the product of step 202 to obtain a polyaniline-active metal oxide-C / carbon support layer.

[0035] Furthermore, step 2 satisfies at least one of the following conditions:

[0036] (1) In step 201, the concentration of the acidic aqueous solution is 0.5 to 3 mol / L;

[0037] Optionally, the acidic aqueous solution is a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution or a nitric acid aqueous solution;

[0038] (2) In step 201, after adding aniline, the concentration of aniline in the acidic aqueous solution is 0.5 mol / L-10 mol / L;

[0039] (3) In step 202, the concentration of the ammonium persulfate aqueous solution is 0.4 mol / L-5 mol / L;

[0040] The volume ratio of the ammonium persulfate aqueous solution to the solution in step 201 is 1:2 to 5:1;

[0041] (4) The drying in step 203 is carried out in a vacuum drying oven at 40-100° C. for 1-24 hours.

[0042] In one possible design, the conductive polymer is polypyrrole, and step 2 includes:

[0043] 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;

[0044] Step 202', adding ferric chloride aqueous solution to solution A, and continuing the reaction at 0-7°C for 1-24 hours;

[0045] Step 203 ′: washing and drying the product of step 202 ′ to obtain a polypyrrole-active metal oxide-C / carbon support layer.

[0046] Furthermore, step 2 satisfies at least one of the following conditions:

[0047] (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;

[0048] (2) The surfactant is sodium dodecylbenzenesulfonate;

[0049] (3) the concentration of the ferric chloride aqueous solution is 0.02-0.2 mol / L;

[0050] The volume ratio of the ferric chloride aqueous solution to solution A is 1:2 to 5:1.

[0051] In one possible design, the conductive polymer is polythiophene, and step 2 includes:

[0052] Step 201″, adding ferric chloride to a trichlorotoluene solution to prepare a solution B, placing the active metal oxide-C / carbon support layer in the solution B, and stirring at 0-7°C;

[0053] Step 202": add thiophene to solution B and react at 0-7°C for 24 hours;

[0054] Step 203 ″: wash and dry the product of step 202 ″ to obtain a polythiophene-active metal oxide-C / carbon support layer.

[0055] Furthermore, step 2 satisfies at least one of the following conditions:

[0056] (1) In step 201″, the concentration of ferric chloride in solution B is 0.5-1 mol / L;

[0057] (2) In step 202″, the mass ratio of thiophene added to ferric chloride is 1:(4-6).

[0058] Furthermore, the step 3 includes: rolling the metal lithium foil onto the conductive polymer-active metal oxide-C / carbon support layer.

[0059] Furthermore, the step 3 includes: 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.

[0060] In a second aspect, the present invention provides a three-dimensional lithium metal negative electrode prepared according to the above method.

[0061] In a third aspect, the present invention provides a lithium-ion battery comprising the above-mentioned three-dimensional lithium metal negative electrode.

[0062] Furthermore, before step 1, the carbon support layer is pretreated, and the pretreatment includes:

[0063] A. Place the carbon support layer in a mixed solution of concentrated nitric acid and concentrated sulfuric acid at 50-80°C for 1-6 hours. After the reaction, rinse the carbon support layer with deionized water until the water is neutral, thereby obtaining a hydrophilic carbon support layer.

[0064] B. The hydrophilic carbon support layer is ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 1-20 minutes, repeated 2-10 times, and then taken out and dried in a vacuum drying oven at 40-100° C. for 1-24 hours.

[0065] The technical solution of the present invention has the following advantages:

[0066] 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 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 prepare the three-dimensional lithium metal negative electrode.

[0067] 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.

[0068] The present invention uses a carbon support layer with a three-dimensional structure as a substrate material, and grows an active metal oxide-C and a conductive polymer on its surface to ultimately form a conductive polymer-active metal oxide-C / carbon support layer. 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 the conductive polymer can improve the contact between lithium and the 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.

[0069] The present invention, through the synergistic effects of the conductive polymer, carbon support layer, and ZnO, exhibits excellent flexibility, ionic conductivity, and electrical conductivity, effectively improving lithium ion migration and transport. ZnO has a strong affinity for lithium, significantly improving the lithium wettability of the carbon cloth. The space in the carbon support layer not only allows for lithium pre-storage but also acts as a buffer for lithium expansion, ensuring uniform lithium ion distribution, thereby inhibiting the growth of lithium dendrites and improving the electrochemical performance of the lithium battery. The conductive polymer further buffers lithium volume expansion to a certain extent and improves the contact between lithium and the solid electrolyte. DETAILED DESCRIPTION

[0070] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0071] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0072] The carbon cloths in the examples and comparative examples were purchased from Shanghai Hesen Electric Co., Ltd.

[0073] Example 1

[0074] This embodiment provides a method for preparing a three-dimensional lithium metal anode, comprising the following steps:

[0075] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0076] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0077] (3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0078] (4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

[0079] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0080] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0081] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0082] (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), and then stirred at 0°C for 2 h.

[0083] (9) Dissolve 5.7 g of ammonium persulfate in 50 ml of deionized water.

[0084] (10) Slowly add the solution in step (9) to step (8). After complete addition, continue the reaction at 0°C for 24 hours.

[0085] (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.

[0086] (12) A 0.05 mm thick lithium metal foil was slowly rolled onto the polyaniline-ZnO-C / carbon cloth to obtain a Li-polyaniline-ZnO-C / carbon cloth composite lithium negative electrode.

[0087] Example 2

[0088] This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of Example 1, except that:

[0089] (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 electroplated onto polyaniline-ZnO-C / carbon cloth to obtain a Li-polyaniline-ZnO-C / carbon cloth composite lithium negative electrode.

[0090] Example 3

[0091] This embodiment provides a method for preparing a three-dimensional lithium metal anode, comprising the following steps:

[0092] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0093] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0094] (3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0095] (4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

[0096] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0097] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0098] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0099] (8) The ZnO-C / carbon obtained in step (7) was placed in 50 ml of deionized water containing 1.74 g of sodium dodecylbenzenesulfonate and 3.35 g of pyrrole, and then stirred at a low temperature of 5°C for 2 h.

[0100] (9) Dissolve 0.5 g of ferric chloride in 50 ml of deionized water.

[0101] (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.

[0102] (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.

[0103] (12) A 0.05 mm thick lithium metal foil was slowly rolled onto the polypyrrole-ZnO-C / carbon cloth to obtain a Li-polypyrrole-ZnO-C / carbon cloth composite lithium negative electrode.

[0104] Example 4

[0105] This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of Example 3, except that:

[0106] (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 deposited on polypyrrole-ZnO-C / carbon cloth to obtain a Li-polypyrrole-ZnO-C / carbon cloth composite lithium negative electrode.

[0107] Example 5

[0108] This embodiment provides a method for preparing a three-dimensional lithium metal anode, comprising the following steps:

[0109] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0110] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0111] (3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0112] (4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

[0113] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0114] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0115] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0116] (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.

[0117] (9) Slowly add 1 g of thiophene liquid into (8) and react at low temperature of 0°C for 24 hours.

[0118] (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.

[0119] (11) A 0.05 mm thick lithium metal foil was slowly rolled onto the polythiophene-ZnO-C / carbon cloth to obtain a Li-polythiophene-ZnO-C / carbon cloth composite lithium negative electrode.

[0120] Example 6

[0121] This embodiment provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of Example 5, except that:

[0122] (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 a Li-polythiophene-ZnO-C / carbon cloth composite lithium negative electrode.

[0123] Example 7

[0124] This embodiment provides a method for preparing a three-dimensional lithium metal anode, comprising the following steps:

[0125] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0126] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0127] (3) 3 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solution of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0128] (4) Dissolve 1.5 g of zinc nitrate in 100 ml of deionized water.

[0129] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0130] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0131] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0132] (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 placed in a low temperature of 5°C and stirred for 2 h.

[0133] (9) Dissolve 8.6 g of ammonium persulfate in 50 ml of deionized water.

[0134] (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.

[0135] (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.

[0136] (12) A 0.05 mm thick lithium metal foil was slowly rolled onto the polyaniline-ZnO-C / carbon cloth to obtain a Li-polyaniline-ZnO-C / carbon cloth composite lithium negative electrode.

[0137] Comparative Example 1

[0138] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

[0139] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0140] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0141] (3) Slowly roll a 0.05 mm thick lithium metal foil onto the hydrophilic carbon cloth to obtain a Li / carbon cloth composite lithium negative electrode.

[0142] Comparative Example 2

[0143] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of comparative example 1, except that:

[0144] (3) Using hydrophilic carbon cloth as the working electrode and metallic lithium sheet as the working electrode and counter electrode, metallic lithium is deposited onto the hydrophilic carbon cloth to obtain a Li-carbon cloth composite lithium negative electrode.

[0145] Comparative Example 3

[0146] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

[0147] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0148] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0149] (3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0150] (4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

[0151] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0152] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0153] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0154] (8) Slowly roll a 0.05 mm thick lithium metal foil onto the ZnO-C / carbon cloth to obtain a Li / ZnO-C / carbon cloth composite lithium negative electrode.

[0155] Comparative Example 4

[0156] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of comparative example 3, except that:

[0157] (8) Using ZnO-C / carbon cloth as the working electrode and metallic lithium sheet as the working electrode and counter electrode, metallic lithium is deposited onto the ZnO-C / carbon cloth to obtain a Li-ZnO-C / carbon cloth composite lithium negative electrode.

[0158] Comparative Example 5

[0159] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

[0160] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0161] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0162] (3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0163] (4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

[0164] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0165] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0166] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0167] (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.

[0168] (9) Slowly roll 0.05 mm metal lithium foil onto polyaniline-ZnO-C / carbon cloth to obtain a Li-polyaniline-ZnO-C / carbon cloth composite lithium negative electrode.

[0169] Comparative Example 6

[0170] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of comparative example 5, except that:

[0171] (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 deposited on polyaniline-ZnO-C / carbon cloth to obtain a Li-polyaniline-ZnO-C / carbon cloth composite lithium negative electrode.

[0172] Comparative Example 7

[0173] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

[0174] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0175] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0176] (3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0177] (4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

[0178] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0179] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0180] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0181] (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.

[0182] (9) A 0.05 mm thick lithium metal foil was slowly rolled onto the polypyrrole-ZnO-C / carbon cloth to obtain a Li-polypyrrole-ZnO-C / carbon cloth composite lithium negative electrode.

[0183] (10) The composite lithium negative electrode and battery-grade copper sheet form a Li-Cu half-cell with a current density of 0.25 mA / cm 2 , the capacity parameter is 0.5mAh / cm 2 , the test results are shown in Table 1.

[0184] Comparative Example 8

[0185] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of comparative example 7, except that:

[0186] (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 polypyrrole-ZnO-C / carbon cloth to obtain a Li-polypyrrole-ZnO-C / carbon cloth composite lithium negative electrode.

[0187] Comparative Example 9

[0188] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, comprising the following steps:

[0189] (1) First, a 5cm*5cm carbon cloth was treated by placing it 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. The mixture was reacted 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.

[0190] (2) The hydrophilic carbon cloth pretreated in (1) was ultrasonically treated in acetone, anhydrous ethanol, and deionized water for 2 minutes, repeated 5 times, and then taken out and dried in a vacuum drying oven at 50°C for 24 hours.

[0191] (3) 1.5 g of 8-hydroxyquinoline was dissolved in 100 ml of a mixed solvent of anhydrous ethanol and benzene, with the volume ratio of anhydrous ethanol to benzene being 4:1, and then the carbon cloth was added.

[0192] (4) Dissolve 1 g of zinc nitrate in 100 ml of deionized water.

[0193] (5) The solution in (4) was added to the solution in (3) and reacted at 80°C for 5 hours.

[0194] (6) After the reaction is completed, the carbon cloth is taken out and washed with anhydrous ethanol and deionized water, respectively, for three times, and then placed in a vacuum drying oven at 80°C for 12 hours to obtain an 8-hydroxyquinoline-zinc / carbon cloth composite.

[0195] (7) The 8-hydroxyquinoline-zinc / carbon cloth composite was placed in a muffle furnace and heat treated at 400 °C for 2 h to obtain ZnO-C / carbon cloth.

[0196] (8) Commercial polythiophene, 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 polythiophene-ZnO-C / carbon cloth.

[0197] (9) Slowly roll a 0.05 mm thick lithium metal foil onto the polythiophene-ZnO-C / carbon cloth to obtain a Li-polythiophene-ZnO-C / carbon cloth composite lithium negative electrode.

[0198] Comparative Example 10

[0199] This comparative example provides a method for preparing a three-dimensional lithium metal negative electrode, which is basically the same as that of comparative example 9, except that:

[0200] (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 polythiophene-ZnO-C / carbon cloth to obtain a Li-polythiophene-ZnO-C / carbon cloth composite lithium negative electrode.

[0201] Test example

[0202] The three-dimensional lithium metal negative electrode prepared in the embodiment and the comparative example was respectively combined with a battery-grade copper sheet to form a Li-Cu half-cell, and the test current density was 0.25 mA / cm 2 , the capacity parameter is 0.5mAh / cm 2 , the test results are shown in Table 1.

[0203] Table 1 Test results of Li-Cu half-cells prepared in Example

[0204]

[0205]

[0206] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing a three-dimensional lithium metal negative electrode, characterized in that: The following steps are involved: 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 prepare the three-dimensional lithium metal anode; The step 3 comprises: rolling the metal lithium foil onto the conductive polymer-active metal oxide-C / carbon support layer; or The step 3 comprises: using a metal lithium sheet as a working electrode and a counter electrode, and electro-depositing metal lithium onto a conductive polymer-active metal oxide-C / carbon support layer; The active metal oxide includes at least one of zinc oxide, tin oxide, and copper oxide; The conductive polymer includes at least one of polyaniline, polypyrrole, and polythiophene; 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 removing the carbon support layer after the reaction; Step 103: Cleaning 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; In step 101, the concentration of 8-hydroxyquinoline after being dissolved in the mixed solvent is 10 mg / mL-100 mg / mL; 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; 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; In step 102, the heating reaction temperature is 40-80° C. and the reaction time is 1-10 hours; In step 103, the drying is: drying in a vacuum drying oven at 40-100° C. for 1-24 hours; In step 104, the calcination condition is a heat treatment at 300-500° C. for 1-5 hours; 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; When the conductive polymer is polyaniline, the step 2 comprises: Step 201: adding an active metal oxide-C / carbon support layer and aniline to 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: washing and drying the product of step 202 to obtain a polyaniline-active metal oxide-C / carbon support layer; In step 201, the concentration of the acidic aqueous solution is 0.5 to 3 mol / L; after adding aniline, the concentration of aniline in the acidic aqueous solution is 0.5 to 10 mol / L; in step 202, the concentration of the ammonium persulfate aqueous solution is 0.4 to 5 mol / L; the volume ratio of the ammonium persulfate aqueous solution to the solution in step 201 is 1:2 to 5:1; the drying in step 203 is performed in a vacuum drying oven at 40 to 100° C. for 1 to 24 hours; When the conductive polymer is polypyrrole, the 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 ferric chloride aqueous solution 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; In solution A, the concentration of the surfactant is 0.05-0.5 mol / L, and the concentration of pyrrole is 0.5-2 mol / L; the surfactant is sodium dodecylbenzenesulfonate; 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 1:2-5:1; When the conductive polymer is polythiophene, the step 2 comprises: Step 201″, adding ferric chloride to a trichlorotoluene solution to prepare a solution B, placing the active metal oxide-C / carbon support layer in the solution B, and stirring at 0-7°C; Step 202": add thiophene to solution B and react at 0-7°C for 24 hours; Step 203 ″, washing and drying the product of step 202 ″ to obtain a polythiophene-active metal oxide-C / carbon support layer; In step 201", the concentration of ferric chloride in solution B is 0.5-1 mol / L; in step 202", the mass ratio of thiophene added to ferric chloride is 1:(4-6).

2. The method for preparing a three-dimensional lithium metal negative electrode according to claim 1, wherein: The polar solvent includes at least one of methanol, ethanol and water.

3. The method for preparing a three-dimensional lithium metal negative electrode according to claim 1, wherein: The non-polar solvent includes at least one of benzene and toluene.

4. The method for preparing a three-dimensional lithium metal negative electrode according to claim 1, wherein: The acidic aqueous solution is a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution or a nitric acid aqueous solution.

5. A three-dimensional lithium metal anode prepared according to the method according to any one of claims 1 to 4.

6. A lithium ion battery comprising the three-dimensional lithium metal anode according to claim 5.

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