A zero-deformation fully-enclosed graphene / oxide composite metal lithium negative electrode with a laminated pore cavity microstructure and a preparation and application thereof

Abstract

The application provides a graphene / oxide composite metal lithium negative electrode with a laminated pore cavity microstructure, zero deformation and full sealing, and a preparation method and application thereof. The preparation method of the negative electrode comprises the following steps: GO aqueous dispersion is dried to obtain a GO film; the GO film is subjected to a reduction reaction to obtain an rGO film; the surface and the interior of the rGO film are loaded with an oxide to obtain an oxide composite rGO film; and the oxide composite rGO film is loaded with metal lithium to obtain the negative electrode. The laminated pore cavity microstructure in the negative electrode material is the key to changing the working principle of the metal lithium negative electrode, the structure limits lithium deposition and stripping in the laminated pore cavity, and avoids interface fracture caused by volume change; and the two-dimensional continuous rGO composite inorganic oxide completely avoids electrolyte penetration and corrosion of lithium metal; for the first time, the lithium metal battery realizes 99.99% to 99.999% lithium deposition and stripping efficiency for 2000 cycles, and has great application prospect.

Description

Technical Field

[0001] This invention belongs to the field of high-energy-density lithium metal battery technology, specifically relating to a graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and full enclosure, as well as its preparation and application. Background Technology

[0002] Lithium metal (Li) is known for its extremely high theoretical capacity (3,860 mAh g). -1 With its lowest electrochemical redox potential (-3.04V vs. SHE), lithium metal is considered the ultimate anode material to replace graphite anodes in high-energy-density rechargeable batteries. However, the poor coulombic efficiency of lithium metal anodes in high-energy-density lithium metal batteries leads to problems such as battery capacity decay, rapid loss of active materials, and short cycle life. Furthermore, achieving a coulombic efficiency greater than 99.9% over 1000 cycles is difficult for lithium metal anodes, severely limiting the development of lithium metal battery technology.

[0003] Current lithium metal anodes face two major challenges: uncontrollable volume changes during lithium deposition and stripping, and the high reactivity of lithium metal with the electrolyte. Many studies have shown that constructing artificial solid electrolyte membranes (SEIs), optimizing electrolyte composition, and developing solid electrolytes can partially improve the high reactivity of lithium metal with the electrolyte. Many research teams have also attempted to alleviate the volume change problem of lithium metal anodes during lithium deposition and stripping by introducing three-dimensional frameworks. However, even within an open framework, a large surface area of ​​the lithium metal anode exposed to the electrolyte inevitably leads to side reactions, and the volume change problem of lithium metal during deposition-dissolution cannot be completely overcome. Currently, no solution to the volume change problem of lithium metal anodes has been reported worldwide, which is the fundamental reason for the poor cycle reversibility and low coulombic efficiency of contemporary lithium metal anodes.

[0004] Therefore, reducing the volume change mechanism in the deposition-dissolution electrochemical reaction process of lithium metal anode from a relatively infinite volume change to zero, while avoiding exposure of lithium metal to corrosive electrolyte, will be an effective method to achieve lithium deposition / stripping efficiency greater than 99.9% and realize highly reversible lithium metal anodes. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a stacked porous microstructure, zero-deformation, fully enclosed graphene / oxide composite lithium metal anode, along with its preparation and applications. The stacked porous microstructure in the composite lithium metal anode material of this invention is key to changing the working principle of lithium metal anodes. This structure confines lithium within the stacked porous cavity for deposition and stripping, avoiding interfacial fracture caused by volume changes. Furthermore, the two-dimensional continuous rGO composite inorganic oxide completely prevents electrolyte penetration and corrosion of the lithium metal. For the first time, a lithium deposition / stripping efficiency of 99.99% to 99.999% over 2000 cycles has been achieved in lithium metal batteries, demonstrating significant application potential.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for preparing a graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure, comprising the following steps:

[0008] (1) GO aqueous dispersion was dried to prepare GO film;

[0009] (2) GO film was reduced to obtain rGO film;

[0010] (3) Oxide composite rGO films are obtained by loading oxides on the surface and inside the rGO film;

[0011] (4) Lithium metal is loaded onto oxide composite rGO thin films to obtain graphene / oxide composite lithium metal anodes with stacked cavity microstructure, zero deformation, and full enclosure.

[0012] According to a preferred embodiment of the present invention, in step (1), the mass concentration of the GO aqueous dispersion is 1-100 mg / g.

[0013] According to a preferred embodiment of the present invention, in step (1), the drying temperature is 20-100°C.

[0014] According to a preferred embodiment of the present invention, in step (1), the thickness of the GO film is 10-500 μm.

[0015] According to a preferred embodiment of the present invention, step (1) of the method for preparing the GO film includes the steps of: uniformly coating a GO aqueous dispersion onto a mold and drying it to obtain a GO film. Preferably, the mold is a quartz glass plate.

[0016] According to a preferred embodiment of the present invention, in step (2), the method for preparing the rGO film includes the following steps: reducing the GO film with a reducing agent or subjecting it to high-temperature heat treatment to obtain the rGO film; wherein the reducing agent is a 5wt%-50wt% aqueous solution of hydrogen iodide, a 5wt%-50wt% aqueous solution of sodium ascorbate, or hydrazine hydrate vapor; the mass ratio of the reducing agent to the GO film is 0.5-5:1, the reduction reaction temperature is 50-500℃, and the reduction reaction time is 1-48h; the high-temperature heat treatment temperature is 100-3000℃, the high-temperature heat treatment atmosphere is nitrogen or argon, and the high-temperature heat treatment time is 0.01-1000 minutes. Preferably, the high-temperature heat treatment temperature is 250-350℃, and the high-temperature heat treatment time is 0.01-1 minute.

[0017] According to a preferred embodiment of the present invention, step (2) further includes a rolling step after the reduction reaction, so that the thickness of the rGO film is 1-300 μm.

[0018] According to a preferred embodiment of the present invention, in step (3), the oxide is ZnO, Al2O3, TiO2, MoO2 or Co2O3.

[0019] According to a preferred embodiment of the present invention, in step (3), the method for preparing the oxide composite rGO thin film includes the following steps: depositing an oxide layer with a thickness of 10-500 nm on the surface and inside of the rGO thin film using atomic layer deposition to obtain an oxide composite rGO thin film; preferably, the thickness of the oxide layer is 70-300 nm, and more preferably 225-300 nm.

[0020] According to a preferred embodiment of the present invention, step (4) of the preparation method of the graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and full enclosure includes the following steps: contacting the four edges of the oxide composite rGO film, melting lithium metal for 0.5-10 s, and then allowing it to stand at 250-450°C for 5-30 minutes to allow the lithium metal to diffuse uniformly into the interior of the oxide composite rGO film, thereby obtaining the graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and full enclosure. Because the oxide composite rGO film has a large number of nanopores and a lithium-loving oxide layer, the molten lithium metal will diffuse uniformly into the interior of the oxide composite rGO film according to capillary action.

[0021] A graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure was prepared by the above method.

[0022] According to a preferred embodiment of the present invention, the graphene / oxide composite lithium metal anode is a lithium metal loaded within the internal cavity of a multilayered porous microstructured oxide composite rGO film; the multilayered porous microstructured oxide composite rGO film consists of oxides loaded on the surface and inside the multilayered porous microstructured rGO film.

[0023] The above-mentioned stacked cavity microstructure, zero deformation, and fully enclosed graphene / oxide composite lithium metal anode are applied in lithium metal batteries.

[0024] According to a preferred embodiment of the present invention, the positive electrode of the lithium metal battery is lithium cobalt oxide, a ternary nickel-cobalt-manganese layered material, lithium iron phosphate, lithium titanate, a layered lithium-rich manganese-based positive electrode material, or a layered lithium manganese oxide (LiMnO2); the separator is selected from glass-carbon fiber, polypropylene separator, or polyethylene separator; the solute of the electrolyte is selected from one or more combinations of lithium hexafluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium nitrate, or lithium polysulfide; the solvent of the electrolyte is selected from one or more combinations of 1,3-dioxapentane, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethyl carbonate, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether, 1,1,2,3,3,3-hexafluoropropyl-2,2,2-trifluoroethyl ether, or 1,1,1,2,2,3,4,5,5,5-decafluoropentane; the lithium metal battery packaging includes a button cell, a pouch cell, or a stainless steel cell.

[0025] The technical features and beneficial effects of this invention are as follows:

[0026] (1) The present invention uses atomic layer vapor deposition to uniformly load oxide layers onto the surface and interior of rGO, and not limited to the surface of rGO. This oxide coating can enhance the ionic conductivity of the composite anode and enhance the lithium ion transport capability. It has the advantages of uniform oxide layer thickness, high stability and large-scale preparation.

[0027] (2) The stacked cavity microstructure in the composite lithium metal anode material of the present invention is the key to changing the working principle of the lithium metal anode. This structure confines lithium to the stacked cavity for deposition and stripping, completely suppressing the volume change and interface damage problems during the deposition and dissolution process of lithium metal anode; and the two-dimensional continuous rGO composite inorganic oxide completely avoids the side reactions caused by electrolyte penetration and corrosion of lithium metal.

[0028] (3) In summary, the graphene / oxide composite lithium metal anode prepared by this invention has the advantages of high specific energy and long life. Furthermore, the application of this in-situ constructed electrode material with adjustable composition and thickness in lithium metal batteries significantly improves the cycle reversibility and coulombic efficiency of lithium metal batteries, achieving a lithium deposition / stripping efficiency of 99.99% to 99.999% for up to 2000 cycles, which has great application prospects. Attached Figure Description

[0029] Figure 1 SEM images of the composite lithium metal anodes prepared in Example 1(a) and Comparative Example 1(b);

[0030] Figure 2 Half-cell cycle performance of the composite lithium metal anodes prepared in Example 1 and Comparative Example 1;

[0031] Figure 3 The full-cell cycle performance of the composite lithium metal anodes prepared in Example 1 and Comparative Example 1;

[0032] Figure 4 SEM images of the composite lithium metal anodes prepared in Example 1 and Comparative Example 1 under different cycle conditions in the full cells.

[0033] Figure 5 X-ray photoelectron spectroscopy depth etching images of the composite lithium metal anodes prepared in Example 1 and Comparative Example 1 after full cell cycling.

[0034] Figure 6 The image shows the in-situ pressure test results of the pouch cells with composite lithium metal anodes prepared in Example 1 and Comparative Example 1. Detailed Implementation

[0035] The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0036] Example 1

[0037] A method for preparing a graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure, comprising the following steps:

[0038] Step 1: Preparation of GO film: Using a quartz glass plate, a 10 mg / g GO aqueous solution was uniformly coated onto the glass plate and allowed to air dry at room temperature to obtain a GO film with a thickness of 300 μm.

[0039] Step 2, preparation of rGO film: Place the GO film on a high-temperature heating stage at 300°C for 1 second in an argon-filled glove box. After removing a large number of oxygen functional groups in GO, an rGO film with a stacked cavity microstructure is obtained. After rolling, an rGO film with a thickness of about 50 μm is obtained.

[0040] Step 3: Deposit ZnO film on the surface and inside of rGO film: Using an atomic layer deposition (ALD) device, place the rGO film with stacked cavity microstructure in a chamber at 150°C and deposit for 800 cycles. Deposit 300nm ZnO film on the surface and inside of the rGO film to obtain a ZnO composite rGO film with stacked cavity microstructure.

[0041] Step 4: Preparation of lithium metal composite anode: Lithium foil is heated on a high-temperature heating stage at 350℃ to obtain molten lithium. The edge of the ZnO composite rGO film with stacked cavity microstructure obtained in Step 3 is brought into contact with the molten lithium metal for 5 seconds. Then, it is placed in a heating chamber at 300℃ for 15 minutes to allow lithium to diffuse uniformly into the interior of the composite film. The lithium metal is stored in the ZnO composite rGO cavity. Then, it is cooled to room temperature to obtain a graphene / oxide composite lithium metal anode with stacked cavity microstructure, zero deformation, and full enclosure, namely, two-dimensional continuous Li@rGO&ZnO.

[0042] Step 5: Assembly of the lithium metal battery: The obtained Li@rGO&ZnO composite support was used as the negative electrode, and assembled with a commercial ternary nickel-cobalt-manganese layered positive electrode (LiNi5Co2Mn3O2(NCM523)), a Celgard 2325 separator, and a locally high-concentration electrolyte (molar ratio of LiFSI:DME:TTE = 1:1.2:3). The specific capacity of the positive electrode was 3.06 mAh cm⁻¹. -2 The ratio of negative to positive capacity in a full cell (R) N / P The value is 2.3, thus obtaining the lithium metal CR2032 coin cell, i.e., the NCM523 full cell.

[0043] Example 2

[0044] A method for preparing a graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure, as described in Example 1, except that in step three, ZnO is replaced with Al2O3; the specific steps are as follows: using an atomic layer deposition (ALD) device, a 300 nm Al2O3 film is deposited on the surface and inside of the rGO film to obtain an Al2O3 composite rGO film with a stacked porous microstructure.

[0045] The remaining steps and conditions are the same as in Example 1.

[0046] Example 3

[0047] A method for preparing a graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure, as described in Example 1, except that in step three, ZnO is replaced with TiO2; the specific steps are as follows: using an atomic layer deposition (ALD) device, a 300 nm TiO2 film is deposited on the surface and inside of the rGO film to obtain a TiO2 composite rGO film with a stacked cavity microstructure.

[0048] The remaining steps and conditions are the same as in Example 1.

[0049] Example 4

[0050] A method for preparing a graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure, as described in Example 1, except that in step three, ZnO is replaced with Co2O3; the specific steps are as follows: using an atomic layer deposition (ALD) device, a 300 nm Co2O3 film is deposited on the surface and inside of the rGO film to obtain a Co2O3 composite rGO film with a stacked porous microstructure.

[0051] The remaining steps and conditions are the same as in Example 1.

[0052] Example 5

[0053] A method for preparing a graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure is described in Example 1, except that in step three, an atomic layer deposition (ALD) device is used to place the rGO film with the stacked porous microstructure in a chamber at 150°C for 200 cycles, and a 75nm ZnO film is deposited on the surface and inside of the rGO film to obtain a ZnO composite rGO film with a stacked porous microstructure.

[0054] The remaining steps and conditions are the same as in Example 1.

[0055] Example 6

[0056] A method for preparing a graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure is described in Example 1, except that in step three, an atomic layer deposition (ALD) device is used to place the rGO film with the stacked porous microstructure in a chamber at 150°C for 400 cycles, and a 150nm ZnO film is deposited on the surface and inside of the rGO film to obtain a ZnO composite rGO film with a stacked porous microstructure.

[0057] The remaining steps and conditions are the same as in Example 1.

[0058] Example 7

[0059] A method for preparing a graphene / oxide composite lithium metal anode with a stacked porous microstructure, zero deformation, and fully enclosed structure is described in Example 1, except that in step three, an atomic layer deposition (ALD) device is used to place the rGO film with the stacked porous microstructure in a chamber at 150°C for 600 cycles, and a 225nm ZnO film is deposited on the surface and inside of the rGO film to obtain a ZnO composite rGO film with a stacked porous microstructure.

[0060] The remaining steps and conditions are the same as in Example 1.

[0061] Comparative Example 1

[0062] A method for preparing a structurally disrupted composite lithium metal anode, as described in Example 1, except that step (iii) is omitted, and the rGO film obtained in step (ii) is directly used to load lithium metal, and then the structure is completely disrupted using a cell disruptor to obtain a structurally disrupted composite lithium metal anode; the specific steps are as follows:

[0063] The preparation of the GO thin film is the same as step (I) in Example 1;

[0064] The preparation of the rGO thin film is the same as step (II) in Example 1;

[0065] Step 3: Preparation of the lithium metal composite anode: Lithium foil was heated on a high-temperature heating stage at 350℃ to obtain molten lithium. The edge of the rGO film obtained in Step 2 was brought into contact with the molten lithium metal for 5 seconds, and then placed in a heating chamber at 300℃ for 15 minutes to allow lithium to diffuse uniformly into the interior of the rGO film. The film was then cooled to room temperature to obtain the composite lithium metal anode. The structure was completely destroyed using a cell disruptor to obtain the structurally destroyed composite lithium metal anode (random Li@rGO&ZnO).

[0066] The assembly method of the lithium metal CR2032 button cell is the same as step (v) in Example 1.

[0067] Experimental Example 1

[0068] (1) SEM of the composite lithium metal anodes prepared in Example 1 and Comparative Example 1.

[0069] like Figure 1 As shown, both Example 1 and Comparative Example 1 have a thickness of 50 μm. The difference is that Example 1 has a regular layered structure, while Comparative Example 1 does not have a layered structure. This is due to the destruction of the structure during sample preparation.

[0070] (2) Half-cell battery performance test

[0071] Using the composite lithium metal anode prepared in Examples 1, 5-7 or Comparative Example 1 as the anode, and the electrolyte as a locally high-concentration electrolyte (molar ratio of LiFSI:DME:TTE = 1:1.2:3), a half-cell was constructed.

[0072] Depend on Figure 2 A comparison shows that the Li|| composite negative electrode half-cells of Example 1 and Comparative Example 1 perform well at 1 mA / cm². -2 Current density and 1mAh cm -2 Under the surface capacity, the average coulombic efficiency of Example 1 remained at around 99.99%-99.999% after about 2000 cycles, while the average coulombic efficiency of Comparative Example 1 was around 95.05435% after about 900 cycles.

[0073] As can be seen from the comparison in Table 1, composite anodes with different deposition cycles have different half-cell coulombic efficiencies.

[0074] Table 1. Half-cell coulombic efficiency of composite anodes with different deposition cycles.

[0075] Number of sedimentary rings Half-cell coulombic efficiency (first 200 cycles) 200 (Example 5) 99.23％ 400 (Example 6) 99.44％ 600 (Example 7) 99.59％ 800 (Example 1) 99.99％

[0076] (3) Full battery performance test

[0077] The performance of the NCM523 full cells prepared in Example 1 and Comparative Example 1 was tested.

[0078] Depend on Figure 3 As can be seen from the comparison, Example 1 has a capacity retention rate of 89% after about 700 cycles at 0.5C, while Comparative Example 1 has a capacity retention rate of 80% after 136 cycles at 0.5C.

[0079] (4) Next, the sample thicknesses of Example 1 and Comparative Example 1 were compared. The composite negative electrode of the half-cell constructed in (2) under different cycling conditions was imaged using a scanning electron microscope. Figure 4 As can be seen from ae, Example 1 at 1mAh cm -2 The thickness remained unchanged at 50 μm after Li stripping and deposition, and was within 1 mAh cm⁻¹. -2 The thickness remained unchanged after 400 cycles. However, as... Figure 4 As can be seen from fj, Comparative Example 1 is at 1mAh cm -2 The thickness of the Li deposited and stripped layers changed to 18.9 μm and 25.1 μm, respectively (representing 62.2% and 49.8% of the original thickness).

[0080] (5) Construct a half-cell as described in (2); in 1 mAh cm⁻¹ -2 Li was stripped off, and the stripped negative electrode sample was etched using ion beams with different etching times. X-ray photoelectron spectroscopy depth etching patterns show (…). Figure 5Example 1 illustrates a bilayer SEI structure, where the outer layer is composed of organic materials derived from the electrolyte, while the inner layer is derived from lithium-modified 0VCCS rGO & ZnO (a special graphene-zinc oxide composite material), which is an inorganic material. In contrast, the SEI layer of Comparative Example 1 exhibits a distribution pattern dominated by organic components derived from the electrolyte across its entire thickness, rich in organic carbon derived from the electrolyte and fluorine-based components. This contrasts sharply with the SEI constructed from lithium-modified 0VCCS rGO & ZnO, which exhibits superior stability and electrolyte isolation capabilities. This indicates that the electrolyte cannot penetrate the continuous two-dimensional SEI layer formed in Example 1. This means that this SEI structure remains stable and does not break even during the extensive lithium deposition and stripping process.

[0081] (6) Assemble a pouch cell using the composite negative electrode of Example 1 or Comparative Example 1, a commercial lithium titanate positive electrode, a Celgard 2325 separator, and a locally high-concentration electrolyte (molar ratio of LiFSI:DME:TTE = 1:1.2:3). Perform in-situ pressure testing on the pouch cell. Figure 6 As can be seen from the comparison, the pressure in Example 1 remained constant during the lithium deposition and stripping process, at around 440 kPa, indicating that Example 1 achieved zero volume change very well. In contrast, Comparative Example 1 showed a huge pressure change during the lithium deposition and stripping process, indicating that the lithium anode underwent a volume change during the deposition and dissolution process, resulting in the rupture of the solid electrolyte interface and exposing metallic lithium to side reactions with the electrolyte. This is also the reason for the low coulombic efficiency and rapid capacity decay.

[0082] In summary, this invention provides a method for preparing a composite lithium metal anode material of rGO and inorganic oxide with a stacked cavity microstructure and zero deformation fully enclosed characteristics, and its application in lithium metal batteries. This achieves a lithium deposition / stripping efficiency of 99.99% to 99.999% for up to 2000 cycles in lithium metal batteries, and has great application potential.

[0083] The above description is only a preferred embodiment of the present invention. The implementation of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure, comprising the following steps: (1) GO aqueous dispersion was dried to prepare GO film; (2) GO film is reduced to obtain rGO film; after reduction reaction, there is also a rolling step to make the thickness of rGO film 1-300 µm; (3) The oxide composite rGO film is obtained by loading oxides on the surface and inside of the rGO film; the oxide is ZnO; the preparation method of the oxide composite rGO film includes the following steps: depositing an oxide layer of 150-300 nm on the surface and inside of the rGO film using atomic layer deposition to obtain the oxide composite rGO film; (4) Lithium metal is loaded onto oxide composite rGO thin film to obtain a graphene / oxide composite lithium metal anode with stacked cavity microstructure, zero deformation and full enclosure.

2. The method for preparing the graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure according to claim 1, characterized in that, Step (1) includes one or more of the following conditions: i. The mass concentration of the GO aqueous dispersion is 1-100 mg / g; ii. The drying temperature is 20-100℃; iii. The thickness of the GO film is 10-500 µm; iii. The preparation method of GO film includes the following steps: uniformly coating a GO aqueous dispersion onto a mold and drying it to obtain a GO film; the mold is a quartz glass plate.

3. The method for preparing the graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure according to claim 1, characterized in that, In step (2), the preparation method of rGO film includes the following steps: GO film is reduced by a reducing agent or subjected to high temperature heat treatment to obtain rGO film; wherein, the reducing agent is 5wt%-50wt% hydrogen iodide aqueous solution, 5wt%-50wt% sodium ascorbate aqueous solution or hydrazine hydrate vapor; the mass ratio of reducing agent to GO film is 0.5-5:1, the reduction reaction temperature is 50-500℃, the reduction reaction time is 1-48h; the high temperature heat treatment temperature is 100-3000℃, the high temperature heat treatment atmosphere is nitrogen or argon, and the high temperature heat treatment time is 0.01-1000 minutes.

4. The method for preparing the graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure according to claim 3, characterized in that, The high-temperature heat treatment temperature is 250-350℃, and the high-temperature heat treatment time is 0.01-1 minute.

5. The method for preparing the graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure according to claim 1, characterized in that, In step (4), the preparation method of the graphene / oxide composite lithium metal anode with stacked cavity microstructure, zero deformation, and full enclosure includes the following steps: contacting the four edges of the oxide composite rGO film with molten lithium metal for 0.5-10s, and then letting it stand at 250-450℃ for 5-30 minutes to allow the lithium metal to diffuse uniformly into the interior of the oxide composite rGO film, thereby obtaining the graphene / oxide composite lithium metal anode with stacked cavity microstructure, zero deformation, and full enclosure.

6. A graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure, prepared by any one of claims 1-5.

7. The graphene / oxide composite lithium metal anode with a stacked cavity microstructure, zero deformation, and fully enclosed structure according to claim 6, characterized in that, The graphene / oxide composite lithium metal anode is a lithium metal loaded inside the cavity of the oxide composite rGO film with a stacked porous microstructure; the oxide composite rGO film with a stacked porous microstructure consists of oxides loaded on the surface and inside the rGO film with a stacked porous microstructure.

8. The application of the graphene / oxide composite lithium metal anode with stacked cavity microstructure, zero deformation, and fully enclosed structure as described in claim 6 in lithium metal batteries.

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