Electrode with artificial interface protection layer, preparation method thereof and alkali metal battery

Abstract

The present invention discloses an electrode with an artificial interface protective layer, a preparation method thereof, and an alkali metal battery, and relates to the technical field of lithium batteries. The artificial interface protective layer provided by the present invention contains a specific ratio of alkali metal palygorskite (such as Li-Pal) and thermoplastic polyurethane elastomer (TPU). Li-Pal, which has a negative charge characteristic on the surface, exhibits excellent Li + Affinity, can reduce Li + The concentration gradient promotes uniform Li deposition. The high elasticity of TPU inhibits the growth and penetration of lithium dendrites during cycling. Meanwhile, the hydrogen bonds formed between the Si-O of Li-Pal and the N-H of TPU significantly enhance the structural stability of the protective layer. Electrodes modified with this hybrid layer outperform their bare counterparts, exhibiting high mechanical stability and the ability to inhibit lithium (or sodium) dendrite growth. This improves battery cycling performance and demonstrates excellent practicality and economic value.

Description

Technical Field

[0001] The present invention relates to the technical field of alkali metal batteries, and in particular to an electrode with an artificial interface protective layer, a preparation method thereof, and an alkali metal battery. Background Art

[0002] The growing demand for high energy density rechargeable batteries requires the development of new electrode materials and advanced battery systems. Lithium metal has an ultra-high specific capacity (3860 mAh g -1 ) and the lowest electrochemical potential (-3.04 V vs. SHE), making it an ideal candidate for lithium battery anode. However, certain challenges caused by the unstable interface between the lithium metal anode and the organic electrolyte have hindered the commercial application of lithium metal batteries. The host-free characteristics of lithium metal usually lead to unacceptable volume expansion, which further promotes uncontrollable lithium dendrite growth. The rapid growth of lithium dendrites during cycling can pierce the separator, especially under high current density conditions, causing serious safety hazards. In addition, the severe parasitic reactions between lithium metal and solvent molecules continuously consume lithium sources and electrolytes, resulting in low coulombic efficiency of the battery. Moreover, during the plating / stripping process, the volume change of the lithium anode will cause the fragile solid electrolyte interface (SEI) to continue to break and rebuild, resulting in increased polarization and capacity decay of the battery.

[0003] In order to solve the interface problem of lithium metal anode, the main optimization methods are electrolyte optimization and artificial interface engineering strategy. Electrolyte optimization can be achieved by changing the solvent composition or introducing Li + Functional additives diffused into the SEI are used to improve the stability and ionic conductivity of the SEI. However, the low Young's modulus of the in situ formed SEI is not enough to prevent dendrites from penetrating during repeated cycles. Recently, there has been great interest in constructing artificial SEI on lithium anodes by introducing inorganic or organic materials to improve the mechanical strength. For example, Guo et al. reported polyrotaxane-co-acrylic acid (PRPAA) polymer as an adaptive interfacial layer that exhibited a strong ability to self-heal cracks during cycling. However, this artificial interfacial layer only "passively" alleviated the battery fluctuations caused by dendrite growth, but lacked the ability to regulate Li + From the perspective of the Li nucleation and growth mechanism, Li + The mass transfer behavior in the electrolyte has a significant impact on the morphology of Li deposition. + The diffusion limitation induces a large space charge layer near the negative electrode surface and Li + Concentration gradient is the main reason for the appearance of lithium dendrites. Dendrites will pierce the uneven and fragile SEI, and contact with the electrolyte will further accelerate the growth of dendrites. Some inorganic materials have been reported to alleviate concentration polarization and promote Li +However, the interfacial layer composed of these inorganic components and the common PVDF binder exhibits brittleness and shatters under stress.

[0004] Therefore, there is an urgent need to develop high mechanical properties and good Li + An artificial interface layer with strong affinity is formed to inhibit the growth of lithium dendrites, thereby improving the cycle performance of the battery.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide an electrode with an artificial interface protective layer, a preparation method thereof, and an alkali metal battery, aiming to provide an artificial interface protective layer with high mechanical properties and the ability to inhibit lithium dendrite growth, so as to improve the cycle performance of the battery.

[0007] The present invention is achieved in that:

[0008] In a first aspect, the present invention provides an electrode with an artificial interface protective layer, comprising an electrode substrate, wherein the artificial interface protective layer is formed on the surface of the electrode substrate, wherein the artificial interface protective layer comprises alkali metal palygorskite and a thermoplastic polyurethane elastomer, wherein the mass ratio of the alkali metal palygorskite to the thermoplastic polyurethane elastomer is 1:(5-20);

[0009] The alkali metal palygorskite is obtained by ion exchange between a lithium salt solution or a sodium salt solution and palygorskite.

[0010] In an optional embodiment, the mass ratio of the alkali metalized palygorskite to the thermoplastic polyurethane elastomer is 1:(7-11).

[0011] In an optional embodiment, the electrode substrate is at least one of metallic lithium, alloy lithium, or a negative electrode sheet;

[0012] The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer loaded on the negative electrode current collector, and the negative electrode active material in the negative electrode active material layer is selected from nano silicon, micro silicon, SiO x and at least one of a silicon-carbon material;

[0013] And / or, the thickness of the artificial interface protection layer is 3 μm-8 μm.

[0014] In a second aspect, the present invention provides a method for preparing an electrode having an artificial interface protective layer according to any one of the aforementioned embodiments, comprising: mixing alkali metal palygorskite, a thermoplastic polyurethane elastomer, and a first solvent to obtain a slurry;

[0015] The slurry is coated on the electrode substrate and then dried.

[0016] In an optional embodiment, the mass ratio of the total weight of the alkali metal palygorskite and the thermoplastic polyurethane elastomer to the first solvent is (5-15):100;

[0017] And / or, the first solvent is selected from at least one of N-methylpyrrolidone, N,N-dimethylformamide and dimethyl sulfoxide.

[0018] In an optional embodiment, the drying temperature is 60° C.-100° C., and the drying time is 10 h-20 h.

[0019] In an optional embodiment, the preparation process of alkali metal palygorskite includes: mixing an alkali metal salt, palygorskite and water and stirring for 10 hours to 15 hours, then separating the solid and liquid to obtain a solid material, and washing and drying the solid material;

[0020] Wherein, the alkali metal salt is a lithium salt or a sodium salt.

[0021] In an optional embodiment, the process of drying the solid material includes: first drying at 60° C.-120° C. for 8 h-16 h, and then drying at 180° C.-220° C. for 2 h-4 h.

[0022] In an optional embodiment, the electrode substrate is at least one of metallic lithium, alloy lithium, or a negative electrode sheet;

[0023] The preparation process of the negative electrode sheet includes: mixing the negative electrode active material, the conductive agent and the binder, homogenizing to obtain the negative electrode slurry, coating the negative electrode slurry on the negative electrode current collector, and then drying.

[0024] In a third aspect, the present invention provides an alkali metal battery, comprising an electrode with an artificial interface protective layer according to any one of the aforementioned embodiments or an electrode with an artificial interface protective layer prepared by the preparation method according to any one of the aforementioned embodiments, with the electrode with the artificial interface protective layer serving as the negative electrode.

[0025] The present invention has the following beneficial effects: The artificial interface protective layer provided by the present invention contains a specific ratio of alkali metal palygorskite (such as Li-Pal or Na-Pal) and thermoplastic polyurethane elastomer (TPU). Taking Li-Pal as an example, Li-Pal with negative surface charge characteristics shows excellent Li + Affinity, can reduce Li +The concentration gradient promotes uniform Li deposition. The high elasticity of TPU inhibits the growth and penetration of lithium dendrites during cycling. Meanwhile, the hydrogen bonds formed between the Si-O of Li-Pal and the NH of TPU significantly enhance the structural stability of the protective layer. Electrodes modified with this hybrid layer outperform their bare counterparts, exhibiting high mechanical stability and the ability to inhibit lithium (or sodium) dendrite growth. This improves battery cycling performance and demonstrates excellent practicality and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 is the structural formula of the thermoplastic polyurethane elastomer (TPU) used in the embodiments of the present invention;

[0028] Figure 2 is the XRD pattern of palygorskite before and after lithiation;

[0029] Figure 3 High-resolution XPS spectra of Li- pal: (a) Al 2p, (b) Si 2p, (c) Mg 1s and (d) Li1s;

[0030] Figure 4 FT-IR images of pure TPU and LPT artificial interface protective layer;

[0031] Figure 5 The figure shows the cycling stability test results of LiFePO4 full batteries with bare lithium and LPT@Li electrodes at a rate of 5C;

[0032] Figure 6 The figure shows the cycling stability test results of LiFePO4 full batteries with bare lithium and LPT@Li electrodes at a 2C rate;

[0033] Figure 7 The cycling stability test results of NCM811 full batteries with bare lithium and LPT@Li electrodes at a rate of 0.5C are shown;

[0034] Figure 8 For symmetric cells using ether electrolytes, bare lithium and LPT@Li electrodes were tested at 1 mA cm -2 and 1 mAh cm -2 Conditional constant current charge and discharge cycle life test results diagram;

[0035] Figure 9 Symmetrical cells with bare lithium and LPT@Li electrodes using ester electrolytes at 1 mA cm -2 and 1 mAh cm -2 Conditional constant current charge and discharge cycle life test results chart. DETAILED DESCRIPTION

[0036] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0037] An embodiment of the present invention provides an electrode with an artificial interface protective layer, comprising an electrode substrate with an artificial interface protective layer formed on the surface of the electrode substrate. The artificial interface protective layer comprises alkali metal palygorskite and thermoplastic polyurethane (TPU). The alkali metal palygorskite is obtained by ion exchange between a lithium salt solution or a sodium salt solution and palygorskite. For example, it can be lithiated palygorskite Li-Pal or sodium palygorskite Na-Pal. Li-Pal is used as an example for the following description.

[0038] It should be noted that the present invention combines excellent mechanical elasticity and high efficiency Li + The materials with high affinity are simultaneously integrated into this artificial SEI, and the LPT layer (formed by Li-Pal and TPU) achieves dendrite-free Li deposition and achieves long-term cycling stability of lithium metal batteries. Specifically, the negatively charged nature of the Li-Pal surface ensures that Li + The continuous supply of lithium metal anodes weakens the concentration gradient and promotes uniform lithium deposition. The highly elastic TPU ensures that the interface layer adapts to volume changes during cycling. The resulting LPT layer has been shown to address the interfacial instability issue of lithium metal anodes, demonstrating excellent practicality and economic value.

[0039] Thermoplastic polyurethane elastomer (TPU) is a commercially available material, such as that available from Wanhua Chemical Group Co., Ltd., and its structural formula is as follows: Figure 1 As shown, there are soft segments and hard segments, and the values of x and y are not limited.

[0040] Furthermore, the mass ratio of the alkali metal palygorskite to the thermoplastic polyurethane elastomer is 1:(5-20), such as 1:5, 1:7, 1:8, 1:9, 1:10, 1:11, 1:13, 1:15, 1:18, 1:20, and the like, preferably 1:(7-11). A mass ratio of the alkali metal palygorskite to the thermoplastic polyurethane elastomer within this range can better inhibit the growth of lithium dendrites (or sodium dendrites), thereby further improving the cycling performance of the battery.

[0041] In some embodiments, the electrode substrate is at least one of metallic lithium, alloy lithium, or a negative electrode plate. The electrode substrate can be any one or more of the above. The metallic lithium and alloy lithium can be commercially available materials. The negative electrode plate can be prepared by conventional methods, for example: the negative electrode plate includes a negative electrode current collector and a negative electrode active material layer loaded on the negative electrode current collector. The negative electrode active material in the negative electrode active material layer is selected from nano-silicon, micro-silicon, SiO x and at least one of silicon-carbon materials, and the negative electrode active material can be any one or more of the above. Specifically, SiO x The x in the formula is greater than or equal to 1. When x=1, it represents silicon monoxide.

[0042] In some embodiments, the thickness of the artificial interface protection layer is 3 μm-8 μm, such as 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, etc.

[0043] An embodiment of the present invention provides a method for preparing an electrode having an artificial interface protective layer, comprising the following steps:

[0044] S1. Providing alkali metal palygorskite

[0045] The alkali metal palygorskite can be lithiated palygorskite Li-Pal or sodium palygorskite Na-Pal. The preparation process of the alkali metal palygorskite includes mixing and stirring an alkali metal salt, palygorskite, and water for 10-15 hours (e.g., 10 hours, 12 hours, 15 hours, etc.) to complete an ion exchange process, followed by solid-liquid separation to obtain a solid material, which is then washed and dried to obtain the alkali metal palygorskite. The alkali metal salt is a lithium salt or a sodium salt, and both sodium and lithium salts are suitable for the above-mentioned ion exchange method.

[0046] In some embodiments, solid-liquid separation can be achieved by filtration or other methods, and the process of drying the obtained solid material includes: first drying at 60°C-120°C for 8h-16h, and then drying at 180°C-220°C for 2h-4h, to fully remove water through a two-stage drying process. Specifically, the drying temperature of the first drying stage can be 60°C, 80°C, 100°C, 120°C, etc., and the drying time can be 8h, 10h, 12h, 14h, 16h, etc.; the drying temperature of the second drying stage can be 180°C, 200°C, 220°C, etc., and the drying time can be 2h, 3h, 4h, etc.

[0047] S2. Pulping

[0048] The alkali metal palygorskite, thermoplastic polyurethane elastomer and a first solvent are mixed to obtain a slurry. The type of the first solvent is not limited, and can be at least one of N-methylpyrrolidone, N,N-dimethylformamide and dimethyl sulfoxide, and specifically any one or more of the above.

[0049] In some embodiments, the mass ratio of the total weight of the alkali metalized palygorskite and the thermoplastic polyurethane elastomer to the first solvent is (5-15):100, such as 5:100, 8:100, 10:100, 12:100, 15:100, etc. The amount of the first solvent is preferably within the above range, so that the alkali metalized palygorskite and the thermoplastic polyurethane elastomer are evenly dispersed, making it easier to control the coating thickness.

[0050] S3, coating, drying

[0051] The slurry obtained in step S2 is coated on the electrode substrate and then dried to obtain an electrode with an artificial interface protective layer. The coating thickness is determined according to the thickness of the artificial interface protective layer, so that the thickness of the artificial interface protective layer meets the requirements, such as 3μm-8μm.

[0052] In some embodiments, the drying temperature is 60°C-100°C, and the drying time is 10 hours-20 hours. The drying temperature and time are adjusted to fully remove the first solvent. Specifically, the drying process can be heating the slurry-coated electrode in an argon glove box. The drying temperature can be 60°C, 80°C, 100°C, etc., and the drying time can be 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, etc.

[0053] In some embodiments, the electrode substrate is at least one of metallic lithium, a lithium alloy, or a negative electrode sheet. The electrode substrate can be any one or more of the above. The negative electrode sheet preparation process includes: mixing and homogenizing the negative electrode active material, a conductive agent, and a binder to obtain a negative electrode slurry; applying the negative electrode slurry to the negative electrode current collector; and then drying. The type and amount of the conductive agent and binder are not limited. For example, the conductive agent can be conductive carbon black, and the binder can be PVDF (polyvinylidene fluoride).

[0054] An embodiment of the present invention provides an alkali metal battery, comprising an electrode with an artificial interface protective layer provided by an embodiment of the present invention. The electrode with the artificial interface protective layer is used as a negative electrode. Through the improvement of the negative electrode, the battery has high mechanical stability and the ability to inhibit dendrite growth.

[0055] Alkali metal batteries may further include a separator, an electrolyte, and a positive electrode, the specific types of which are not limited.

[0056] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0057] Example 1

[0058] This embodiment provides a method for preparing an electrode having an artificial interface protective layer, and preparing a lithium electrode modified with an LPT artificial interface protective layer (LPT@Li), the steps are as follows:

[0059] (1) 1 g of lithium chloride (LiCl) and 5 g of Pal were added to 50 mL of deionized water. The mixture was mechanically stirred at room temperature for 12 h, and then filtered to obtain a solid material. The solid material was washed with deionized water. The washed sample was dried at 80 °C for 12 h and finally dried at 200 °C for 3 h to obtain Li-Pal.

[0060] (2) 0.1 g of Li-Pal and TPU were added to 1 g of N-methylpyrrolidone (NMP) solvent and stirred for 30 min to obtain a slurry. The mass ratio of Li-Pal to TPU was 1:9.

[0061] (3) The slurry obtained in step (2) was applied to a clean lithium foil (500-1000 μm thick) using a doctor blade to evenly coat the surface. The slurry was then heated at 80°C in an argon glove box for 12 h to obtain a lithium ion-polymerized (LPT) layer-modified lithium electrode (LPT@Li). Scanning electron microscopy (SEM) analysis revealed a 5 μm thickness for the artificial interface protective layer.

[0062] Example 2

[0063] The preparation method of the lithium electrode modified with the LPT artificial interface protection layer (LPT@Li) refers to Example 1, except that the mass ratio of Li-Pal to TPU is 1:19.

[0064] Example 3

[0065] The preparation method of the lithium electrode modified with the LPT artificial interface protection layer (LPT@Li) refers to Example 1, except that the mass ratio of Li-Pal to TPU is 1:5.67.

[0066] Example 4

[0067] The preparation method of the lithium electrode modified with the LPT artificial interface protective layer (LPT@Li) is similar to that in Example 1, except that the mass ratio of Li-Pal to TPU is 1:12.

[0068] Example 5

[0069] The preparation method of the lithium electrode modified with the LPT artificial interface protection layer (LPT@Li) refers to Example 1, except that the mass ratio of Li-Pal to TPU is 1:15.

[0070] Example 6

[0071] The preparation method of the lithium electrode modified with the LPT artificial interface protection layer (LPT@Li) refers to Example 1, except that the mass ratio of Li-Pal to TPU is 1:17.

[0072] Comparative Example 1

[0073] This comparative example provides a Li electrode that is not modified with an LPT artificial interface protection layer, that is, the clean lithium foil used in Example 1.

[0074] Comparative Example 2

[0075] The only difference from Example 1 is that TPU is not introduced, that is, in step (2), TPU is replaced by an equal amount of Li-Pal.

[0076] Comparative Example 3

[0077] The only difference from Example 1 is that Li-Pal is not introduced, that is, in step (2), Li-Pal is replaced by an equal amount of TPU.

[0078] Comparative Example 4

[0079] The only difference from Example 1 is that TPU is replaced by an equal amount of polyvinylidene fluoride (PVDF).

[0080] Test Example 1

[0081] The XRD patterns of palygorskite before and after lithiation in Test Example 1 are as follows: Figure 2 As shown, it can be seen that the XRD patterns of the two are consistent with the standard pattern (PDF#29-0855), proving that lithiation does not change the structure of palygorskite.

[0082] The high-resolution XPS pattern of the lithiated palygorskite in Test Example 1 is as follows: Figure 3 As shown in the figure, it can be seen that the Li 1s spectrum can be fitted into a peak with a binding energy of 57.4 eV, which is consistent with the Li + The characteristic peaks of the ions correspond to those of the ions in the lithiated palygorskite.

[0083] The FT-IR images of the pure TPU and LPT artificial interface protective layers in Test Example 1 are as follows: Figure 4 As shown, NH can be seen from 3326 cm -1 Redshift to 3322 cm -1 , which is due to the formation of hydrogen bonds between TPU and Li-Pal, further improving the mechanical strength.

[0084] Test Example 2

[0085] The electrodes of the embodiment and comparative example were used to prepare lithium metal batteries and were tested. The specific steps were as follows:

[0086] (1) The positive electrode active material lithium nickel cobalt manganese oxide LiNi 0.8 Co 0.1 Mn 0.1 The positive electrode slurry formed by mixing O2 or lithium iron phosphate, conductive agent carbon black, and binder polyvinylidene fluoride in a weight ratio of 8:1:1 is coated on the positive electrode current collector Al foil, and the positive electrode sheet is obtained after drying and rolling.

[0087] (2) In an argon protective atmosphere with an oxygen content and a water content of less than 1 ppm, 1 M LiPF6 was dissolved in a mixed solution of ethylene carbonate and diethyl carbonate in a volume ratio of 1:1 to obtain a uniform organic ester electrolyte; 1 M LiTFSI was dissolved in a mixed solution of dioxolane and ethylene glycol dimethyl ether in a volume ratio of 1:1, and 1 wt% LiNO3 was added thereto to obtain a uniform organic ether electrolyte.

[0088] (3) Assembling button-type batteries in a glove box where the water and oxygen content is less than 1 ppm, the battery shell model is a 2025 battery shell; the ester electrolyte prepared in step (2) is dripped onto the surface of the diaphragm, and the positive electrode battery shell, positive electrode sheet, diaphragm, negative electrode sheet, and negative electrode battery shell are stacked in order and packaged.

[0089] (4) Charge-discharge cycle performance test: Full batteries (LPT@Li||LFP, Li||LFP) were assembled using the electrode sheets of the embodiment and comparative example as the negative electrode sheets and the lithium iron phosphate electrode sheets as the positive electrode sheets. The charge-discharge cycle performance was tested at 2C (LFP active material loading 9.8 mg cm -2 ) and 5C (LFP active material loading 3.6 mg cm -2 ) rate, the charge and discharge cycle performance test was carried out at a charge and discharge cut-off voltage of 2.5-4V; the electrode sheets of the embodiment and the comparative example were used as the negative electrode sheet, LiNi 0.8 Co 0.1 Mn 0.1 The O2 electrode sheet was used as the positive electrode to assemble the full cell (LPT@Li||NCM811, Li||NCM811, active material loading 3.6 mg cm -2 ) Charge and discharge cycle performance tests were carried out at a rate of 0.5C and a charge and discharge cut-off voltage of 2.7-4.3V.

[0090] The electrodes prepared in Examples 1-3 were used to assemble Li||Li symmetrical batteries with the ether electrolyte and ester electrolyte prepared in step (2) at 1 mA cm -2 and 1 mAh cm -2 The cycle life is tested by constant current charge and discharge under the same conditions.

[0091] The cycle performance test results of the embodiments and comparative examples are shown in Tables 1 and Figure 4-Figure 9 :

[0092] Table 1 Cyclic performance test results of Examples and Comparative Examples

[0093]

[0094] By comparing Examples 1-3 with the comparative example, it can be seen that the LPT artificial interface protective layer selected in the present invention has high mechanical strength and good Li + affinity, significantly inhibiting the growth of lithium dendrites. Compared with bare lithium, LiFePO4 and LiNi 0.8 Mn 0.1 Co 0.1 The full battery assembled with O2 and LPT@Li electrodes provides excellent lifespan in long-term and high-current cycling. It was found that the LPT layer obtained when the mass ratio of Li-Pal to TPU was 1:9 was the best, showing good practicality and economic benefits.

[0095] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An electrode having an artificial interface protective layer, characterized in that: The invention comprises an electrode substrate, wherein an artificial interface protection layer is formed on the surface of the electrode substrate, wherein the artificial interface protection layer comprises alkali metal palygorskite and thermoplastic polyurethane elastomer, and the mass ratio of the alkali metal palygorskite to the thermoplastic polyurethane elastomer is 1:(7-11); Wherein, the alkali metal palygorskite is obtained by ion exchange between lithium salt solution or sodium salt solution and palygorskite; The electrode substrate is at least one of metallic lithium, alloy lithium or a negative electrode plate; the thickness of the artificial interface protection layer is 3 μm-8 μm.

2. The electrode with an artificial interface protective layer according to claim 1, characterized in that: The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer loaded on the negative electrode current collector, wherein the negative electrode active material in the negative electrode active material layer is selected from nano silicon, micro silicon, SiO x and at least one of silicon-carbon materials.

3. A method for preparing an electrode having an artificial interface protective layer according to any one of claims 1 to 2, characterized in that: include: mixing alkali metalized palygorskite, thermoplastic polyurethane elastomer and a first solvent to obtain a slurry; The slurry is coated on an electrode substrate and then dried.

4. The preparation method according to claim 3, characterized in that The mass ratio of the total weight of the alkali metal palygorskite and the thermoplastic polyurethane elastomer to the first solvent is (5-15):100; And / or, the first solvent is selected from at least one of N-methylpyrrolidone, N,N-dimethylformamide and dimethyl sulfoxide.

5. The preparation method according to claim 3, characterized in that The drying temperature is 60℃-100℃, and the drying time is 10h-20h.

6. The preparation method according to claim 3, characterized in that The preparation process of the alkali metal palygorskite comprises: mixing an alkali metal salt, palygorskite and water and stirring for 10 hours to 15 hours, then separating the solid and liquid to obtain a solid material, and washing and drying the solid material; Wherein, the alkali metal salt is a lithium salt or a sodium salt.

7. The preparation method according to claim 6, characterized in that The process of drying the solid material includes: first drying at 60° C.-120° C. for 8 h-16 h, and then drying at 180° C.-220° C. for 2 h-4 h.

8. The preparation method according to claim 3, characterized in that The electrode substrate is at least one of metallic lithium, alloy lithium or a negative electrode sheet; The preparation process of the negative electrode sheet includes: mixing and homogenizing the negative electrode active material, the conductive agent and the binder to obtain a negative electrode slurry, coating the negative electrode slurry on the negative electrode current collector, and then drying.

9. An alkali metal battery, characterized in that: The invention comprises an electrode with an artificial interface protective layer as described in any one of claims 1-2 or an electrode with an artificial interface protective layer prepared by the preparation method according to any one of claims 3-8, and the electrode with an artificial interface protective layer is used as a negative electrode.

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