Preparation method for interpenetrating solid electrolyte interface and use thereof

Abstract

A preparation method for an interpenetrating solid electrolyte interface and the use thereof in the technical field of battery materials. The preparation method comprises: preparing a lithium oxide coating from a lithium metal electrode sheet in an air atmosphere; immersing same in a lithium polysulfide plating solution to prepare a lithium sulfide coating; and then drying same at room temperature to obtain a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface. By means of a simple chemical oxidation reduction method, a double-layer artificial SEI structure is designed to solve the problems, such as volume expansion in cycles, non-uniform lithium deposition, lithium dendrite growth, low coulombic efficiency, and bad long cycle stability, of lithium metal negative electrodes, improving effects in the application to lithium ion batteries.

Description

Preparation method and application of interpenetrating solid electrolyte interface Technical Field

[0001] The present invention belongs to the technical field of battery materials, and more particularly relates to a preparation method and application of an interpenetrating solid electrolyte interface. Background Art

[0002] The continuous depletion of non-renewable energy sources such as oil and natural gas is exacerbating the global energy crisis. Technological advancement and improved living standards are inseparable from energy. The booming development of portable electronic devices and new energy electric vehicles has created an urgent need for high-capacity anode materials suitable for rechargeable lithium-based batteries with high energy / power density. This has brought metallic lithium, once considered the "holy grail" of battery technology, marginalized in the 1990s due to the commercialization of graphite anodes, back into the limelight of scientists. Because of its highest theoretical specific capacity and lowest redox potential, it is the ultimate choice for next-generation lithium-ion batteries. However, the uncontrolled growth of lithium dendrites during battery cycling seriously affects the cycling stability, safety, and practical applicability of lithium metal batteries.

[0003] Problems such as volume expansion of lithium metal negative electrodes during cycling, uneven lithium deposition, lithium dendrite growth, low Coulombic efficiency, and poor long-cycle stability are difficulties that technicians in this field have been working hard to solve in order to achieve better battery performance.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method and application of an interpenetrating solid electrolyte interface. Through a simple chemical redox method, a double-layer artificial SEI structure is designed, which solves the problems existing in the above-mentioned prior art and effectively inhibits the growth of lithium dendrites during the charge and discharge process.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is to provide a method for preparing an interpenetrating solid electrolyte interface, comprising the following steps:

[0008] A lithium metal electrode is prepared into a lithium oxide coating in an air atmosphere, and then immersed in a lithium polysulfide plating solution to prepare a lithium sulfide coating, and then dried to obtain the interpenetrating solid electrolyte interface.

[0009] Furthermore, the lithium metal pole piece is a polished lithium metal pole piece.

[0010] Furthermore, the step of preparing the lithium oxide coating includes: exposing the lithium metal electrode to air with a humidity of 30% to 80% for 1 second to 600 seconds.

[0011] Furthermore, the preparation step of the lithium polysulfide plating solution includes: using sublimed sulfur and lithium sulfide as solutes and an electrolyte as a solvent to prepare a lithium polysulfide plating solution with a concentration of 0.1 to 10 mol / L.

[0012] Preferably, the molar ratio of the sublimated sulfur to lithium sulfide is 1 to 7:1.

[0013] Preferably, the electrolyte is an ether electrolyte or a lipid electrolyte.

[0014] More preferably, the ether electrolyte is composed of a lithium salt solute and an electrolyte solvent; wherein the lithium salt solute is at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6) and lithium nitrate (LiNO3); the electrolyte solvent is at least two of tetrahydrofuran (THF), 2-methyltetrahydrofuran (2me-thf), 1,3-dioxolane (DOL), dimethoxymethane (DMM), 1,2-dimethoxyethane (DME) and diethylene glycol dimethyl ether (DG).

[0015] More preferably, the lipid electrolyte consists of a lithium salt solute and an electrolyte solvent; wherein the lithium salt solute is at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4) and lithium hexafluoroarsenate (LiAsF6); and the electrolyte solvent is at least two of ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC).

[0016] Furthermore, the step of preparing the lithium sulfide coating includes: immersing the lithium metal electrode having the lithium oxide coating in the lithium polysulfide plating solution for 1 second to 600 seconds.

[0017] Furthermore, the drying is performed at room temperature in an inert environment.

[0018] The second technical solution of the present invention is to provide an interpenetrating solid electrolyte interface prepared by the above preparation method.

[0019] The third technical solution of the present invention is to provide an application of the above-mentioned interpenetrating solid electrolyte interface in a lithium-ion battery.

[0020] The fourth technical solution of the present invention: provides a negative electrode plate, including the above-mentioned interpenetrating solid electrolyte interface.

[0021] The fifth technical solution of the present invention: provides a full battery, including the above-mentioned negative electrode plate.

[0022] Technical solution six of the present invention: provides a symmetrical battery, including the above-mentioned negative electrode plate.

[0023] The present invention discloses the following technical effects:

[0024] The present invention prepares a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface, effectively combining the ability of lithium oxide to reduce the lithium ion diffusion energy barrier with the ability of lithium sulfide to inhibit the growth of lithium dendrites, achieving a superlinear synergistic effect of 1+1>2.

[0025] The lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface prepared by the present invention improves the exchange current density and reduces the membrane resistance, thereby ensuring that lithium ions are quickly and evenly transmitted to the electrode surface during the battery charging and discharging process. This property is crucial for high-performance batteries. The artificial solid electrolyte interface can also inhibit the volume expansion of lithium during the cycle, thereby effectively improving the battery's first coulombic efficiency. The artificial solid electrolyte interface has strong mechanical stability and a dense and uniform surface, thereby effectively inhibiting the growth of lithium dendrites.

[0026] After forming a symmetrical battery or a full battery, the cycle life and long-cycle stability are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings:

[0028] FIG1 is a cross-sectional SEM image of a lithium metal electrode having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface prepared in Example 1;

[0029] FIG2 is a SEM image of a lithium metal button-type electrode sheet having a lithium oxide coating after 150 cycles of a lithium symmetrical battery prepared from the electrode sheet of Comparative Example 1;

[0030] FIG3 is a SEM image of a lithium metal button-type electrode sheet having a lithium sulfide coating after 150 cycles of a lithium symmetric battery prepared from the electrode sheet of Comparative Example 2;

[0031] FIG4 is a SEM image of a lithium metal button-type electrode having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface prepared in Example 1;

[0032] FIG5 is a SEM image of a lithium metal button-type electrode sheet having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface after 150 cycles of a lithium symmetric battery prepared from the electrode sheet of Example 1;

[0033] FIG6 is a SEM image of the original button-type lithium sheet of the control group after 150 cycles of the lithium symmetric battery prepared from the original button-type lithium sheet;

[0034] Figure 7 shows the electrode plates of the control group and Example 1 at a current density of 1 mA / cm 2 And the cycle capacity is 1mAh / cm 2 EIS graph after 150 cycles under the same conditions;

[0035] Figure 8 shows the electrode plates of the control group and Example 1 at a current density of 1 mA / cm 2 And the cycle capacity is 1mAh / cm 2 Tafel plot after 150 cycles under the same conditions;

[0036] FIG9 shows the long cycle results of lithium-ion batteries prepared from the electrode sheets of the control group and Example 1;

[0037] FIG10 shows the cycle performance of the ternary full battery assembled with Example 1 and the original button-type lithium sheet as the negative electrode. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0039] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0040] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0041] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0042] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0043] Unless otherwise specified, the room temperature / normal temperature referred to in the embodiments of the present invention refers to 25±5°C.

[0044] The steps for preparing the lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface of the present invention include:

[0045] S1. Polishing of lithium metal pole pieces

[0046] Use a 500-4000 mesh silver polishing rod and unoxidized lithium metal electrode; polish the surface of the lithium metal electrode to a bright silver finish with the silver polishing rod;

[0047] S2. Preparation of lithium polysulfide plating solution

[0048] Dissolving sublimed sulfur and lithium sulfide in an ether or lipid electrolyte at a molar ratio of 1 to 7:1 to prepare a lithium polysulfide plating solution with a concentration of 0.1 to 10 mol / L;

[0049] The ether electrolyte is composed of a lithium salt solute and an electrolyte solvent; wherein the lithium salt solute is at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6) and lithium nitrate (LiNO3); the electrolyte solvent is at least two of tetrahydrofuran (THF), 2-methyltetrahydrofuran (2me-thf), 1,3-dioxolane (DOL), dimethoxymethane (DMM), 1,2-dimethoxyethane (DME) and diethylene glycol dimethyl ether (DG);

[0050] The lipid electrolyte is composed of a lithium salt solute and an electrolyte solvent; wherein the lithium salt solute is at least one of lithium hexafluorophosphate (LiPF6), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4) and lithium hexafluoroarsenate (LiAsF6); the electrolyte solvent is at least two of ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC); S3, preparing a lithium oxide coating

[0051] The lithium metal electrode polished in step S1 is exposed to air at room temperature for a time of 1s to 600s and an air humidity of 30% to 80%, preferably 1s to 300s;

[0052] S4. Preparation of lithium sulfide coating

[0053] The lithium metal electrode with the lithium oxide coating obtained in step S3 is immersed in the lithium polysulfide plating solution prepared in step S2 for a time of 1 second to 600 seconds, preferably 1 second to 300 seconds;

[0054] S5. The lithium metal electrode having a lithium sulfide coating and a lithium oxide coating prepared in step S4 is naturally air-dried in a glove box to obtain a lithium metal electrode having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface.

[0055] In a specific embodiment, the molar ratio of sublimated sulfur to lithium sulfide is 1:1. However, it should be noted that the ratio range of 1 to 7:1 specified in the present invention is selected for the purpose of completely reacting the lithium sulfide. Based on the preparation method and principle of lithium polysulfide in this application, the effect on the final lithium polysulfide coating is negligible and can be equivalently replaced.

[0056] In a specific embodiment, the inert gas atmosphere is provided by a glove box.

[0057] Example 1

[0058] Preparation of electrode sheets with interpenetrating solid electrolyte interfaces:

[0059] S1. Polishing of lithium metal pole pieces

[0060] A lithium metal button electrode with a thickness of 1.2 mm and a diameter of 15 mm was selected and polished to a bright finish using a silver polishing rod (mesh size 2000) in a glove box.

[0061] S2. Preparation of lithium polysulfide plating solution

[0062] In a glove box, use a pipette to take 1000mL of electrolyte (1.0M LiTFSI in DOL:DME=3:5Vol% with 1.2%LiNO3), place it in a glass bottle, and seal it tightly. Weigh 0.2mol of sublimed sulfur and 0.2mol of lithium sulfide, and pour them into the glass bottle containing 1000mL of electrolyte in sequence. Then place a clean rotor into the glass bottle and seal it with sealing glue. Place it on a magnetic stirrer and stir it for 4 days at a speed of 600rpm. The final plating solution concentration is 0.2mol / L.

[0063] S3, preparation of lithium oxide coating

[0064] Take the polished lithium metal button electrode from S1 out of the glove box and expose it to air (room temperature, humidity 40%) for 150 seconds; then quickly put it back into the glove box;

[0065] S4. Preparation of lithium sulfide coating

[0066] The lithium metal button electrode with lithium oxide coating obtained in S3 was immersed in the lithium polysulfide plating solution prepared in S2 for 200s;

[0067] S5. The lithium metal electrode having a lithium sulfide coating and a lithium oxide coating prepared in step S4 is naturally air-dried in a glove box for 5 hours to obtain a lithium metal electrode having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface.

[0068] The cross-sectional SEM image of the lithium metal electrode with a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface is shown in Figure 1. It can be seen that the interface between the lithium metal layer and the lithium oxide layer is smooth and has no expansion.

[0069] Example 2

[0070] Preparation of electrode sheets with interpenetrating solid electrolyte interfaces:

[0071] S1. Polishing of lithium metal pole pieces

[0072] A lithium metal button electrode with a thickness of 1.2 mm and a diameter of 15 mm was selected and polished to a bright finish using a silver polishing rod (mesh size 2500) in a glove box.

[0073] S2. Preparation of lithium polysulfide plating solution

[0074] In a glove box, use a pipette to take 1000mL of electrolyte (1.0M LiPF6 inEC:DMC:EMC=5:3:2Vol%), place it in a glass bottle, and seal it tightly. Weigh 0.3mol of sublimated sulfur and 0.3mol of lithium sulfide, and pour them into the glass bottle containing 1000mL of electrolyte in sequence. Then place a clean rotor into the glass bottle and seal it with sealing glue. Place it on a magnetic stirrer and stir it for 5 days at a speed of 700rpm. The final plating solution concentration is 0.3mol / L.

[0075] S3, preparation of lithium oxide coating

[0076] Take the polished lithium metal button electrode from S1 out of the glove box and expose it to air (room temperature, humidity 45%) for 210 seconds; then quickly put it back into the glove box;

[0077] S4. Preparation of lithium sulfide coating

[0078] The lithium metal button electrode with lithium oxide coating obtained in S3 was immersed in the lithium polysulfide plating solution prepared in S2 for 250s;

[0079] S5. The lithium metal electrode having a lithium sulfide coating and a lithium oxide coating prepared in step S4 is naturally air-dried in a glove box for 7 hours to obtain a lithium metal electrode having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface.

[0080] Example 3

[0081] Preparation of electrode sheets with interpenetrating solid electrolyte interfaces:

[0082] S1. Polishing of lithium metal pole pieces

[0083] A lithium metal button electrode with a thickness of 1.2 mm and a diameter of 15 mm was selected and polished to a bright finish using a silver polishing rod (mesh size 3000) in a glove box.

[0084] S2. Preparation of lithium polysulfide plating solution

[0085] In a glove box, use a pipette to take 1000mL of electrolyte (1.0M LiPF6 in EC:DMC:EMC=4:3:3Vol%), place it in a glass bottle, and seal it tightly. Weigh 0.5mol of sublimed sulfur and 0.5mol of lithium sulfide, and pour them into the glass bottle containing 1000mL of electrolyte in sequence. Then, place a clean rotor into the glass bottle and seal it with sealing glue. Place it on a magnetic stirrer and stir it for 6 days at a speed of 750rpm. The final plating solution concentration is 0.5mol / L.

[0086] S3, preparation of lithium oxide coating

[0087] Take the polished lithium metal button electrode from S1 out of the glove box and expose it to air (room temperature, 50% humidity) for 230 seconds; then quickly put it back into the glove box;

[0088] S4. Preparation of lithium sulfide coating

[0089] The lithium metal button electrode with lithium oxide coating obtained in S3 was immersed in the lithium polysulfide plating solution prepared in S2 for 300s;

[0090] S5. The lithium metal electrode having a lithium sulfide coating and a lithium oxide coating prepared in step S4 is naturally air-dried in a glove box for 10 hours to obtain a lithium metal electrode having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface.

[0091] Comparative Example 1

[0092] Preparation of electrode sheets with solid electrolyte interface:

[0093] S1. Polishing of lithium metal pole pieces

[0094] A lithium metal button electrode with a thickness of 1.2 mm and a diameter of 15 mm was selected and polished to a bright finish using a silver polishing rod (mesh size 2000) in a glove box.

[0095] S2. Preparation of lithium oxide coating

[0096] The polished lithium metal button electrode in S1 was taken out of the glove box, exposed to air (room temperature, humidity 40%) for 150 seconds, and then quickly placed back into the glove box to obtain a lithium metal electrode with an artificial solid electrolyte interface.

[0097] Comparative Example 2

[0098] Preparation of electrode sheets with solid electrolyte interface:

[0099] S1. Polishing of lithium metal pole pieces

[0100] A lithium metal button electrode with a thickness of 1.2 mm and a diameter of 15 mm was selected and polished to a bright finish using a silver polishing rod (mesh number 2500) in a glove box.

[0101] S2. Preparation of lithium polysulfide plating solution

[0102] In a glove box, use a pipette to take 1000mL of electrolyte (1.0M LiPF6 in EC:DMC:EMC=5:3:2Vol%), place it in a glass bottle, and seal it tightly. Weigh 0.2mol of sublimated sulfur and 0.2mol of lithium sulfide, and pour them into the glass bottle containing 1000mL of electrolyte in sequence. Then place a clean rotor into the glass bottle and seal it with sealing glue. Place it on a magnetic stirrer and stir it for 4 days at a speed of 600rpm. The final plating solution concentration is 0.2mol / L.

[0103] S3. Preparation of lithium sulfide coating

[0104] Immerse the polished lithium metal button electrode in S1 in the lithium polysulfide plating solution prepared in S2 for 200s;

[0105] S4. The lithium metal electrode with the lithium sulfide coating prepared in step S3 is naturally air-dried in a glove box for 5 hours to obtain a lithium metal electrode with an artificial solid electrolyte interface.

[0106] Test example

[0107] Electrochemical performance test

[0108] 1. Symmetrical battery

[0109] The electrode sheets prepared in Example 1 and Comparative Examples 1-2 and the original button-type lithium sheets were used as negative electrode materials to form lithium symmetrical batteries, and the original button-type lithium sheet group was used as the control group.

[0110] The assembled lithium symmetric battery was tested at a current density of 1 mA / cm 2 And the cycle capacity is 1mAh / cm 2 The surface morphology was characterized after 150 cycles under the same conditions.

[0111] Figure 2 is an SEM image of a lithium metal button-type electrode piece having a lithium oxide coating after 150 cycles of a lithium symmetric battery prepared from the electrode piece of Comparative Example 1; Figure 3 is an SEM image of a lithium metal button-type electrode piece having a lithium sulfide coating after 150 cycles of a lithium symmetric battery prepared from the electrode piece of Comparative Example 2; Figure 4 is an SEM image of a lithium metal button-type electrode piece having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface prepared in Example 1; Figure 5 is an SEM image of a lithium metal button-type electrode piece having a lithium sulfide / lithium oxide interpenetrating artificial solid electrolyte interface after 150 cycles of a lithium symmetric battery prepared from the electrode piece of Example 1;

[0112] Figure 6 shows an SEM image of a lithium symmetric battery prepared from a pristine lithium coin-shaped sheet in the control group after 150 cycles. As can be seen from Figures 2 to 6, this artificial solid electrolyte interface effectively suppresses the formation of lithium dendrites (the SEM images of Examples 2 and 3 are essentially the same as that of Example 1).

[0113] The electrode plates of the control group and Example 1 were 2 And the cycle capacity is 1mAh / cm 2 The EIS graph after 150 cycles under the same conditions is shown in FIG7 , from which it can be seen that the double-layer artificial SEI structure designed in the present invention can effectively reduce the membrane resistance.

[0114] The electrode plates of the control group and Example 1 were 2 And the cycle capacity is 1mAh / cm 2 The Tafel image after 150 cycles under the same conditions is shown in FIG8 . It can be seen that the double-layer artificial SEI structure designed in the present invention can effectively improve the exchange current density.

[0115] The assembled lithium symmetric battery was tested at a current density of 2 mA / cm 2 And the cycle capacity is 5mAh / cm 2 Perform current limiting charge and discharge test.

[0116] Figure 9 shows the long-term cycling results of lithium symmetric batteries prepared from the electrode sheets of the control group and Example 1. As can be seen from Figure 9, the double-layer artificial SEI structure designed in the present invention can effectively reduce the cycling overpotential and increase the cycle life.

[0117] 2. Ternary battery

[0118] Ternary full-cell assembly and testing: The selected ternary materials, NCM811, PVDF, and Super-P, were sequentially added to an NMP solution in a mass ratio of 8:1:1. The mixture was stirred for 4 hours to obtain a uniformly dispersed slurry, which was then coated onto aluminum foil and dried in a 70°C vacuum oven for 12 hours. The resulting sample was cut to the desired size to obtain the ternary electrode sheet. Ternary full-cell batteries were then assembled and tested using the ternary electrode sheet as the positive electrode and Example 1 and the original lithium button sheet as the negative electrode.

[0119] Figure 10 shows the cycle performance of the ternary full battery assembled with Example 1 and the original button-type lithium sheet as the negative electrode. It can be seen from Figure 10 that the double-layer artificial SEI structure designed in the present invention can effectively improve the cycle life and cycle capacity.

[0120] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0121] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing an interpenetrating solid electrolyte interface, characterized in that the steps include: A lithium metal electrode is prepared into a lithium oxide coating in an air atmosphere, and then immersed in a lithium polysulfide plating solution to prepare a lithium sulfide coating, and then dried to obtain the interpenetrating solid electrolyte interface.

2. The preparation method according to claim 1, characterized in that The step of preparing the lithium oxide coating comprises: exposing the lithium metal pole piece to air with a humidity of 30% to 80% for 1 second to 600 seconds.

3. The preparation method according to claim 1, characterized in that The preparation step of the lithium polysulfide plating solution comprises: using sublimed sulfur and lithium sulfide as solutes and electrolyte as solvent to prepare a lithium polysulfide plating solution with a concentration of 0.1 to 10 mol / L.

4. The preparation method according to claim 3, characterized in that The molar ratio of the sublimated sulfur to lithium sulfide is 1 to 7:1; and the electrolyte is an ether electrolyte or a lipid electrolyte.

5. The preparation method according to claim 1, characterized in that The step of preparing the lithium sulfide coating comprises: immersing the lithium metal electrode having the lithium oxide coating in the lithium polysulfide plating solution for 1 second to 600 seconds.

6. An interpenetrating solid electrolyte interface prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the interpenetrating solid electrolyte interface according to claim 6 in a lithium ion battery.

8. A negative electrode plate, characterized in that: Comprising the interpenetrating solid electrolyte interface according to claim 6.

9. A full battery, characterized in that: Including the negative electrode sheet according to claim 8.

10. A symmetrical battery, characterized in that: Including the negative electrode sheet according to claim 8.

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