An integrated alkali metal anode - electrolyte material, its preparation method, and its application in assembling a solid - state battery in air

Abstract

The present invention belongs to the technical field of solid-state batteries, and discloses an application of an alkali metal negative electrode-electrolyte integrated material and a preparation method thereof in assembling a solid-state battery in air. The method is to dissolve or disperse an electrolyte component with an alkali metal protection function in an organic solvent, stir to form an electrolyte slurry, and then coat the slurry on the surface of the alkali metal material in a protective atmosphere. After the organic solvent volatilizes, an alkali metal negative electrode-electrolyte integrated material can be obtained. The process of the present invention is simple and easy to operate, the coating area and thickness of the material are easy to control, and it is easy to mass-produce. The material can effectively block air and water, thereby effectively protecting the alkali metal negative electrode. The material can assemble an alkali metal solid-state battery in an air environment, which can reduce the assembly difficulty and environmental requirements, and further reduce the production cost. The material can also effectively reduce the interfacial contact impedance between the alkali metal negative electrode and the electrolyte, and can inhibit the generation of alkali metal dendrites, improving the cycle stability of the prepared solid-state battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state batteries, and particularly relates to an application of an alkali metal negative electrode-electrolyte integrated material and a preparation method thereof in assembling a solid-state battery in air. Background Art

[0002] While developing clean energy, how to establish a clean and efficient energy storage system, and thus the efficient storage and utilization of energy has become a top priority. With the continuous development of modern consumer electronics, electric vehicles, and fixed-grid energy storage, higher requirements are put forward for the energy density, safety and reliability, and service life of energy storage devices. Alkali metal (lithium, sodium, potassium) ion secondary batteries are currently widely used energy storage devices due to their advantages such as high energy density, long life, environmental protection, and low self-discharge rate. Alkali metal secondary batteries with alkali metals as negative electrodes, including alkali metal-oxide batteries, alkali metal-sulfur batteries, and alkali metal-air batteries, all have high theoretical energy densities and are important development directions in the future energy storage field. However, at present, most alkali metal secondary batteries still use flammable liquid electrolytes, which inevitably have potential safety hazards and also limit the improvement of energy density. Therefore, it is imperative to develop energy storage devices with high safety, high energy density, and multifunctionality.

[0003] Since there is no electrolyte inside solid-state alkali metal batteries, potential safety hazards caused by problems such as electrolyte leakage can be avoided. At the same time, solid-state batteries have advantages such as high energy density and no memory effect, and have received extensive attention from the academic and industrial circles. However, since all-solid-state batteries use alkali metals as negative electrode materials, the latter are extremely prone to react with air, water, etc. in a normal environment of a non-vacuum atmosphere and a non-inert atmosphere. This makes the assembly of all-solid-state alkali metal batteries have high requirements and costs for equipment, environment, and processes, bringing huge challenges to the large-scale production and application of alkali metal solid-state batteries. In addition, compared with traditional liquid batteries, solid-state batteries have a large electrode-electrolyte interface impedance, which seriously affects the electrochemical performance of solid-state batteries. To address this problem, in-situ coating of electrolytes to prepare electrode-electrolyte integrated materials can reduce the interface impedance between the electrode and the electrolyte and improve the electrochemical performance of alkali metal solid-state batteries. Summary of the Invention

[0004] In order to overcome the deficiencies and drawbacks of the prior art, the primary object of the present invention is to provide a preparation method of an alkali metal negative electrode-electrolyte integrated material; using polyvinylidene chloride with high air and water barrier properties, electrolyte salts, and additives with high ionic conductivity as electrolyte components, and by dissolving or dispersing the electrolyte components in an organic solvent to form an electrolyte slurry and then coating it on the surface of an alkali metal material, an alkali metal negative electrode-electrolyte integrated material that can block air and water from eroding the alkali metal can be obtained after removing the organic solvent.

[0005] Another object of the present invention is to provide an alkali metal negative electrode-electrolyte integrated material prepared by the above-mentioned preparation method, which integrates the alkali metal negative electrode and the electrolyte. The prepared electrolyte can prevent air and moisture from contacting the alkali metal, thereby improving the cycle life of the alkali metal solid-state battery.

[0006] Another object of the present invention is to provide an application of the above-mentioned alkali metal negative electrode-electrolyte integrated material to assemble a solid-state battery in the air; the solid-state battery has high energy density, good air stability and safety.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A method for preparing an alkali metal negative electrode-electrolyte integrated material comprises the following steps:

[0009] (1) dissolving the dried electrolyte salt in an organic solvent to obtain a uniform electrolyte salt solution;

[0010] (2) adding an ion conductor component to the electrolyte salt solution obtained in step (1), stirring and dispersing the mixture sufficiently to form a uniform electrolyte slurry;

[0011] (3) The electrolyte slurry is coated on the surface of the alkali metal material in a protective atmosphere, and the alkali metal negative electrode-electrolyte integrated material is obtained after the organic solvent evaporates.

[0012] Preferably, the electrolyte salt in step (1) is one or more of lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluorophosphate (LiPF6), lithium bis(oxalatoborate) (LiBOB), lithium difluorooxalatoborate (LiDFOB), lithium bis(difluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), sodium bicarbonate (NaHCO3), sodium carbonate (Na2CO3), sodium chloride (NaCl), sodium thiocarbonate (Na2S2O3), sodium sulfate (Na2SO4), sodium nitrate (NaNO3), sodium fluoride (NaF), potassium fluoroborate (KBF4), potassium hexafluorophosphate (KPF6), potassium bis(fluorosulfonyl)imide (KFSI), potassium bis(trifluoromethylsulfonyl)imide (KTFSI), potassium perchlorate (KClO4) and potassium trifluoromethanesulfonate (KCF3SO3);

[0013] The organic solvent is tetrahydrofuran (THF), N-methylpyrrolidone (NMP), cyclohexanone (C6H 10 O), N,N-dimethylformamide (DMF), or more thereof.

[0014] Preferably, the ionic conductor component in step (2) includes polyvinylidene chloride (PVDC), ethylene-vinyl acetate copolymer (EVA), or poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). The ionic conductor component also contains an additive, and the content of the additive is 0-20 wt%; the additive is one or more of an organic polymer and an inorganic nanoparticle; the organic polymer is polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and polyethylene oxide (PEO), and the inorganic nanoparticle is one or more of silica, zirconia, titanium dioxide, Li7La3Zr2O 12 、Li 6.4 La3Zr 1.4 Ta 0.6 O 12 、Li 10 GeP2S 12 and one or more of Li6PS5Cl.

[0015] Preferably, the content of the ionic conductor component in the electrolyte slurry in step (2) is 0-60 wt%, and the content of the electrolyte salt component is 5-80 wt%; the process conditions for sufficient stirring and dispersion are: magnetic stirring at 20-30 °C for 2-12 h, and then ultrasonic dispersion at 25-35 °C for 30 min to obtain a uniform electrolyte slurry.

[0016] Preferably, the alkali metal material in step (3) is one of lithium foil, sodium foil, potassium foil, lithium alloy, sodium alloy, and potassium alloy;

[0017] The coating amount of the electrolyte slurry is 10-150 μL / cm 2 ;

[0018] The protective atmosphere is specifically an argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm;

[0019] The process conditions for the evaporation of the organic solvent are: maintaining the temperature at 20-30 °C in an argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm, and naturally evaporating for 12-72 h under the protective atmosphere.

[0020] An alkali metal negative electrode-electrolyte integrated material prepared by the above preparation method, the thickness of the electrolyte membrane in the alkali metal negative electrode-electrolyte integrated material is 5 μm to 150 μm, the content of the ionic conductor in the electrolyte membrane is 55-96 wt%, and the electrolyte salt content is 4-45 wt%.

[0021] A solid-state battery assembled in air based on an alkali metal negative electrode-electrolyte integration, the solid-state battery includes a positive electrode and the above alkali metal negative electrode-electrolyte integrated material, wherein the positive electrode faces the electrolyte side of the alkali metal negative electrode-electrolyte integrated material.

[0022] The active material of the positive electrode is air, sulfur, sulfur / carbon composite or composite metal oxide; the composite metal oxide is Li w Ni x Co y Mn z A (1-x-y-z) O2, LiCo x A (1-x) O2, LiFe x A (1-x) PO4, Na w Ni x Co y Mn z A (1-x-y-z) O2, NaCo x A (1-x) O2, NaFe x A (1-x) PO4, K w Ni x Co y Mn z A (1-x-y-z) O2, KCo x A (1-x) O2 and KFe x A (1-x) One or more of PO4, where A is Al, Sr, Mg, Ti, Ca, Zr, Zn, Si or Fe, 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ z ≤ 1, 0 ≤ w ≤ 2.

[0023] The solid-state battery is assembled in an air environment in the order of a negative electrode case, an alkali metal negative electrode - electrolyte integrated material, a positive electrode, a gasket, a spring piece and a positive electrode case.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] (1) An alkali metal negative electrode - electrolyte integrated material provided by the present invention has good air barrier properties. The main components of the electrolyte used for coating the alkali metal are polyvinylidene chloride (PVDC), ethylene - vinyl acetate copolymer (EVA) or poly(vinylidene fluoride - co - hexafluoropropylene) (PVDF - HFP), which are safe, environmentally friendly and non-toxic, and have good barrier properties, thermal stability and mechanical properties, and can effectively prevent the contact or reaction of alkali metals with air, water, etc.;

[0026] (2) For an alkali metal negative electrode - electrolyte integrated material provided by the present invention, the alkali metal negative electrode - electrolyte integrated material can simultaneously inhibit the growth of alkali metal dendrites and improve the cycle stability of the solid-state battery containing the alkali metal negative electrode - electrolyte integrated material;

[0027] (3) The solid-state battery based on the integrated alkali metal anode - electrolyte that can be assembled in air provided by the present invention includes the above-mentioned integrated alkali metal anode - electrolyte material. This solid-state battery optimizes the battery assembly process of sequentially stacking three independent materials of a traditional alkali metal anode, an electrolyte, and a cathode, and improves it to a battery assembly process of sequentially stacking the integrated alkali metal anode - electrolyte material and the cathode. Moreover, the integrated alkali metal anode - electrolyte material can well improve the interfacial impedance problem between the alkali metal anode and the solid electrolyte, thereby improving the performance of the battery.

[0028] (4) The solid-state battery based on the integrated alkali metal anode - electrolyte that can be assembled in air provided by the present invention includes the above-mentioned integrated alkali metal anode - electrolyte material. A high-load soft-pack battery can be fabricated by a winding process, in which a cathode sheet and an alkali metal anode material with the electrolyte material coated on both sides are stacked in sequence; winding the cathode sheet and the alkali metal anode material with the electrolyte material coated on both sides forms a wound battery cell. The integrated alkali metal anode - electrolyte material can well improve the interfacial impedance problem between the alkali metal anode and the solid electrolyte, thereby improving the performance of the battery.

[0029] (5) The solid-state battery based on the integrated alkali metal anode - electrolyte that can be assembled in air provided by the present invention can be assembled in a room-temperature air environment, which can reduce the assembly difficulty, environmental requirements, and production costs, and is conducive to the large-scale application of solid-state alkali metal batteries.

[0030] (6) The solid-state battery based on the integrated alkali metal anode - electrolyte that can be assembled in air provided by the present invention has good cycle stability and a relatively high capacity at room temperature.

[0031] (7) The integrated alkali metal anode - electrolyte material provided by the present invention can be prepared by slurry coating and solvent evaporation, and the area and thickness of the integrated alkali metal anode - electrolyte material are easy to control.

[0032] (8) The integrated alkali metal anode - electrolyte material provided by the present invention has a simple preparation process and inexpensive raw material sources, and is easy to mass-produce. Description of the Drawings

[0033] Figure 1 It is the coating process for preparing the integrated alkali metal anode - electrolyte material in Examples 1 - 8.

[0034] Figure 2Digital photos of the lithium metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte in Example 1 after contacting air, and digital photos of the surface morphology of the lithium anode after disassembling the solid-state battery assembled based on the lithium metal anode - electrolyte integrated material after several cycles.

[0035] Figure 3 Digital photos of the bare lithium metal anode (left figure), lithium metal anode - electrolyte integrated material with PEO as the main component of the electrolyte (middle figure), and lithium metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte (right figure) immersed in pure water in Example 1 and Comparative Example 1.

[0036] Figure 4 Using the lithium metal anode - electrolyte integrated material with PVDC as the electrolyte as the anode and electrolyte, a lithium metal solid-state battery was assembled by sequentially assembling the positive electrode, gasket, spring sheet, and battery case in a protective atmosphere environment. The positive electrode used was a commercial LFP positive electrode from Kelude, as well as the gasket, spring sheet, and battery case. The performance of the battery was tested using a BTS 7.6.x battery test system produced by Neware Technology Co., Ltd. in Shenzhen, China. The test conditions were a current density of 0.0258 mA cm -2 , a voltage range of 3 - 3.8 V, a test temperature of 25 °C, and a cycle curve graph for the 2nd cycle. The mass of the positive electrode active material was approximately 6.1 mg, and the open-circuit voltage was approximately 2.4 V. The discharge platform of the solid-state battery assembled with this lithium metal anode - electrolyte integrated material was approximately 3.4 V. Its discharge specific capacity in the 2nd cycle was 148 mAh / g, which was close to the theoretical capacity of the LFP positive electrode, and the discharge efficiency in the 2nd cycle was 99%.

[0037] Figure 5 Using the lithium metal anode - electrolyte integrated material with PVDC as the electrolyte as the anode and electrolyte, a lithium metal solid-state battery was assembled by sequentially assembling the positive electrode, gasket, spring sheet, and battery case in the above-mentioned air environment. The positive electrode used was a commercial LFP positive electrode from Kelude, as well as the gasket, spring sheet, and battery case. The performance of the battery was tested using a BTS 7.6.x battery test system produced by Neware Technology Co., Ltd. in Shenzhen, China. The test conditions were a current density of 0.028 mA cm -2 , a voltage range of 3 - 3.8 V, a test temperature of 25 °C, and a cycle curve graph for the 28th - 30th cycles. The mass of the positive electrode active material was approximately 1.2 mg, and the open-circuit voltage was approximately 1.8 V. The discharge platform of the solid-state battery assembled with this lithium metal anode - electrolyte integrated material in the 30th cycle was approximately 3.3 V. Its discharge specific capacity was 61 mAh / g, and the discharge efficiency in the 30th cycle was 95%.

[0038] Figure 6It is a solid-state soft-pack battery based on an integrated lithium metal anode - electrolyte assembled in an air environment with specific air conditions: oxygen content of 21%, air humidity of 51%, and temperature of 28°C.

[0039] Figure 7 It is a digital photo of the lithium metal before and after contacting air in Comparative Example 1, where the left side is before contacting air and the right side is after contacting air.

[0040] Figure 8 It is a digital photo of the integrated lithium metal anode - electrolyte material with PEO as the main component of the electrolyte before and after contacting air in Comparative Example 2, where the left side is before contacting air and the right side is after contacting air. Detailed implementation mode

[0041] The present invention will be further described in detail below in conjunction with the embodiments and the accompanying drawings, but the implementation modes of the present invention are not limited thereto.

[0042] Example 1

[0043] A preparation method of an integrated lithium metal anode - electrolyte material includes the following steps:

[0044] (1) Weigh 0.2 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) after drying, dissolve it in 9.5 g of tetrahydrofuran and stir at 25°C for 12 h. After the electrolyte salt is completely dissolved, a uniform electrolyte salt solution is obtained; weigh 0.5 g of dried polyvinylidene chloride (PVDC) powder, add it to the prepared uniform electrolyte salt solution, and stir at 25°C for 12 h to form a PVDC - LiTFSI electrolyte slurry.

[0045] (2) Transfer the uniformly dissolved or dispersed electrolyte slurry in step (1) to an argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm. In the argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm, coat the electrolyte slurry in step (1) on the surface of the lithium metal sheet at a coating amount of 80 μL cm -2 and perform coating according to the coating process as shown in Figure 1 . After uniform coating, volatilize tetrahydrofuran at 25°C for 48 h to obtain an integrated lithium metal anode - electrolyte material.

[0046] The photo of the integrated lithium metal anode - electrolyte material is as shown in Figure 2As shown on the left side, it can be seen from the figure that the lithium metal anode - electrolyte integrated material is a polymer layer uniformly coated on the surface of the lithium metal. When PVDC is used as the main component of the electrolyte in the alkali metal anode - electrolyte integrated material, the electrolyte membrane has good barrier properties and can play a role in blocking substances such as air and water that are corrosive and reactive to lithium metal. The lithium metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte shows no obvious change on the material surface after being placed in the air at an environmental temperature of 26°C and an air humidity of 51% for 2 minutes. Since the surface color of the alkali metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte is pure white, it is difficult to fully illustrate the oxidation situation on the surface of the lithium metal. Therefore, the full cell assembled with the lithium metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte is cycled several times and then disassembled. The electrolyte coating layer of the lithium metal anode - electrolyte integrated material is mechanically removed. From Figure 2 the right side, it can be seen that the surface of the lithium metal anode still has metallic luster and there is no phenomenon of oxidation and corrosion, indicating that PVDC in the lithium metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte has good protection for the lithium metal anode. To further illustrate the good barrier protection effect of the lithium metal anode - electrolyte integrated material, the lithium metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte is put into water. As Figure 3 shown on the right side, the lithium metal anode - electrolyte integrated material with PVDC as the main component of the electrolyte can maintain a protection duration of more than 6 minutes in water, playing a good role in blocking water.

[0047] Using lithium iron phosphate LiFePO4 as the positive electrode active material, and the lithium metal anode - electrolyte integrated material prepared in this example as the negative electrode and electrolyte, a solid - state lithium metal battery is assembled by sequentially assembling the positive electrode, gasket, spring piece, and battery case. The performance of the battery is tested using the BTS 7.6.x battery test system produced by Neware Co., Ltd., Shenzhen, China. The test conditions are a current density of 0.0258 mA cm -2 , a voltage range of 3 - 3.8 V, and a test temperature of 25°C. As Figure 4 shown, for the solid - state battery assembled with this lithium metal anode - electrolyte integrated material, using a commercial LFP positive electrode, the mass of the positive electrode active material is about 6.1 mg, and the open - circuit voltage is about 2.4 V. The discharge platform of the solid - state battery assembled with this lithium metal anode - electrolyte integrated material is about 3.4 V. The discharge specific capacity of the second cycle is 148 mAh / g, which is close to the theoretical capacity of the LFP positive electrode. The discharge efficiency of the second cycle is 99%. This fully shows that the solid - state battery assembled based on the lithium metal anode - electrolyte integrated material can obtain a relatively high specific capacity during the actual charge - discharge process. The test results show that the described solid - state battery with the lithium metal anode - electrolyte integration has good electrochemical performance.

[0048] Using lithium iron phosphate LiFePO4 as the positive active material, a solid-state full cell was assembled in air with the lithium metal anode-electrolyte integrated material prepared in this example. The specific air conditions were: oxygen content 21%, air humidity 55 - 60%, and temperature 26°C. Using the above-prepared lithium metal anode-electrolyte integrated material as the anode and electrolyte, a lithium metal solid-state soft-pack battery was assembled by sequentially arranging the positive electrode, electrolyte / anode in the above air environment. Its performance was tested using a BTS 7.6.x battery test system produced by Neware Co., Ltd. in Shenzhen, China. The test conditions were 0.1C, voltage range 2.5 - 4V, and test temperature 25°C. As Figure 5 shown, the test results indicate that the described solid-state battery based on alkali metal anode-electrolyte integration that can be assembled in air has good air stability and electrochemical performance.

[0049] Using lithium iron phosphate LiFePO4 as the positive active material, a solid-state full cell was assembled in air with the lithium metal anode-electrolyte integrated material. The specific air conditions were: oxygen content 21%, air humidity 51%, and temperature 28°C. Using the above-prepared lithium metal anode-electrolyte integrated material as the anode and electrolyte, an aluminum-plastic film, an aluminum metal positive electrode current collector and aluminum tabs, a positive electrode, a lithium metal anode-electrolyte integrated material with PVDC as the main component of the electrolyte, a copper metal negative electrode current collector and nickel tabs were sequentially arranged in the above air environment to obtain Figure 6 the shown lithium metal solid-state soft-pack battery assembled in an air environment based on lithium metal anode-electrolyte integration.

[0050] Comparative Example 1

[0051] Lithium metal sheet

[0052] The lithium metal sheet anode was not coated with an electrolyte material. As can be seen from the Figure 7 left side, the fresh lithium metal anode was silver-white with a relatively obvious metallic luster. Figure 7 On the right side was the surface morphology diagram of the lithium metal anode after 2 minutes in air at an ambient temperature of 26°C and an air humidity of 51%. It can be seen that the surface of the lithium metal had turned black and lost its original metallic luster. As time passed, the lithium metal sheet did not return to its original state, but instead the degree of blackening gradually deepened, indicating that the lithium metal sheet had rapidly undergone a continuous and irreversible reaction after contacting air and moisture, generating a substance that could blacken the surface of the lithium metal sheet. This substance was likely lithium nitride produced by the reaction of lithium metal with nitrogen in humid air. Placing the unmodified lithium metal anode into water, as Figure 3The lithium metal anode shown on the left immediately reacted violently with water, producing a large amount of steam bubbles that floated to the surface. As time passed, the lithium metal anode gradually decreased, and within less than 2 minutes of reaction time, the lithium metal anode completely reacted and disappeared in the water.

[0053] Comparative Example 2

[0054] A preparation method of a lithium metal anode - electrolyte integrated material with PEO as the main component of the electrolyte, comprising the following steps:

[0055] (1) Weigh 0.2 g of dried LiTFSI, dissolve it in 9.5 g of tetrahydrofuran, and stir at 25 °C for 12 h. After the electrolyte salt is completely dissolved, a uniform electrolyte salt solution is obtained; weigh 0.5 g of dried polyethylene oxide (PEO) powder, add it to the prepared uniform electrolyte salt solution, and stir at 25 °C for 12 h to form a PEO - LiTFSI electrolyte slurry.

[0056] (2) Transfer the uniformly dissolved or dispersed electrolyte slurry in step (1) to an argon atmosphere with a water content and an oxygen content both ≤ 0.1 ppm. In the argon atmosphere with a water content and an oxygen content both ≤ 0.1 ppm, coat the electrolyte slurry in step (1) on the surface of the lithium metal sheet at a coating amount of 80 μL cm-2, and perform coating according to the coating process as Figure 1 shown. After uniform coating, let the tetrahydrofuran volatilize at 25 °C for 48 h to obtain a lithium metal anode - electrolyte integrated material with PEO as the main component of the electrolyte.

[0057] A photo of the lithium metal anode - electrolyte integrated material with PEO as the main component of the electrolyte is as Figure 8 shown on the left. It can be seen from the figure that the lithium metal anode - electrolyte integrated material is a PEO polymer layer uniformly coated on the surface of the lithium metal. Figure 8 On the right is the surface morphology diagram of the lithium metal anode after 2 minutes in air at an ambient temperature of 26 °C and an air humidity of 51%. It can be observed that when PEO is used as the main component of the electrolyte in the alkali metal anode - electrolyte integrated material, the electrolyte has no obvious protective barrier effect on the lithium metal anode. After the alkali metal anode - electrolyte integrated material with PEO as the electrolyte is placed in air for 2 minutes, the surface of the lithium metal has started to turn black and lost its original metallic luster. As time passes, the lithium metal sheet does not return to its original state, but instead the degree of blackening gradually deepens, indicating that the lithium metal sheet has rapidly undergone a continuous and irreversible reaction after contacting air and moisture, generating a substance that can blacken the surface of the lithium metal sheet. This substance is likely lithium nitride produced by the reaction of lithium metal with nitrogen in humid air. When the lithium metal anode - electrolyte integrated material with PEO as the main component of the electrolyte is placed in pure water, as Figure 3As shown in the middle figure, the lithium metal anode - electrolyte integrated material with PEO as the electrolyte gradually reacted with water, and it only took 3 minutes for a large number of bubbles to emerge from the water surface after the generation of tiny bubbles over time. This indicates that the lithium metal anode - electrolyte integrated material with PEO as the main component of the electrolyte has a certain barrier property, but the barrier property is poor.

[0058] Example 2

[0059] A preparation method of a lithium metal anode - electrolyte integrated material includes the following steps:

[0060] (1) Weigh 0.4 g of dried LiTFSI, dissolve it in 9 g of tetrahydrofuran, and stir at 25 °C for 12 h. After the electrolyte salt is completely dissolved, a uniform electrolyte salt solution is obtained; weigh 0.9 g of dried PVDC powder and 0.10 g of dried PEO powder (Mw = 600,000), add them to the prepared uniform electrolyte salt solution, and stir at 25 °C for 12 h to form a PVDC - PEO - LiTFSI electrolyte slurry.

[0061] (2) Transfer the uniformly dissolved or dispersed electrolyte slurry in step (1) to an argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm. In the argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm, coat the electrolyte slurry in step (1) on the surface of the lithium metal sheet at a coating amount of 90 μL cm -2 and perform the coating according to the coating process as shown, and after uniform coating, let the tetrahydrofuran volatilize at 25 °C for 48 h to obtain a lithium metal anode - electrolyte integrated material. Figure 1

[0062] Using lithium iron phosphate LiFePO4 as the positive electrode active material, and using the above - prepared lithium metal anode - electrolyte integrated material as the negative electrode and electrolyte, assemble the positive electrode, gasket, spring piece, and battery case in sequence to obtain a lithium metal solid - state battery.

[0063] Example 3

[0064] A preparation method of a lithium metal anode - electrolyte integrated material includes the following steps:

[0065] (1) Weigh 0.4 g of dried LiTFSI, dissolve it in 9 g of tetrahydrofuran, and stir at 25 °C for 12 h. After the electrolyte salt is completely dissolved, a uniform electrolyte salt solution is obtained; weigh 0.9 g of dried PVDC powder and 0.10 g of dried PVDF powder, add them to the prepared uniform electrolyte salt solution, and stir at 25 °C for 12 h to form a PVDC - PVDF - LiTFSI electrolyte slurry.

[0066] ​(2) Transfer the uniformly dissolved or dispersed electrolyte slurry described in step (1) to an argon atmosphere with both the water content and oxygen content ≤ 0.1 ppm. In the argon atmosphere with both the water content and oxygen content ≤ 0.1 ppm, coat the electrolyte slurry described in step (1) on the surface of the lithium metal sheet at a coating amount of 90 μL cm -2 , and perform the coating according to the coating process as shown in Figure 1 . After uniform coating, allow tetrahydrofuran to volatilize at 25 °C for 48 h to obtain a lithium metal anode - electrolyte integrated material.

[0067] Using the ternary material LiNi 0.8 Co 0.1 Mn 0.1 O2 (NCM811) as the positive electrode active material, using the above-prepared lithium metal anode - electrolyte integrated material as the negative electrode and electrolyte, assemble the positive electrode, gasket, spring sheet, and battery case in sequence to obtain a lithium metal solid-state battery.

[0068] Example 4

[0069] A preparation method of a lithium metal anode - electrolyte integrated material, comprising the following steps:

[0070] (1) Weigh 0.4 g of dried LiTFSI, dissolve it in 9 g of tetrahydrofuran, and stir at 25 °C for 12 h. After the electrolyte salt is completely dissolved, obtain a uniform electrolyte salt solution; weigh 0.9 g of dried PVDC powder and 0.10 g of dried PVDF-HFP particles, add them to the prepared uniform electrolyte salt solution, and stir at 25 °C for 12 h to form a PVDC-PVDF-HFP-LiTFSI electrolyte slurry.

[0071] (2) Transfer the uniformly dissolved or dispersed electrolyte slurry described in step (1) to an argon atmosphere with both the water content and oxygen content ≤ 0.1 ppm. In the argon atmosphere with both the water content and oxygen content ≤ 0.1 ppm, coat the electrolyte slurry described in step (1) on the surface of the lithium metal sheet at a coating amount of 90 μL cm -2 , and perform the coating according to the coating process as shown in Figure 1 . After uniform coating, allow tetrahydrofuran to volatilize at 25 °C for 48 h to obtain a lithium metal anode - electrolyte integrated material.

[0072] Using the ternary material LiNi 0.8 Co 0.1 Mn 0.1 O2 (NCM811) as the positive electrode active material, using the above-prepared lithium metal anode - electrolyte integrated material as the negative electrode and electrolyte, assemble the positive electrode, gasket, spring sheet, and battery case in sequence to obtain a lithium metal solid-state battery.

[0073] Example 5

[0074] A preparation method of a lithium metal anode - electrolyte integrated material, comprising the following steps:

[0075] (1) Weigh 0.4 g of dried LiTFSI, dissolve it in 9 g of tetrahydrofuran and stir at 25 °C for 12 h. After the electrolyte salt is completely dissolved, a uniform electrolyte salt solution is obtained; weigh 0.85 g of dried PVDC powder and 0.15 g of dried Li7La3Zr2O 12 powder, add it to the prepared uniform electrolyte salt solution, and stir at 25 °C for 12 h to form a PVDC - Li7La3Zr2O 12 -LiTFSI electrolyte slurry.

[0076] (2) Transfer the uniformly dissolved or dispersed electrolyte slurry in step (1) to an argon atmosphere with a water content and an oxygen content both ≤ 0.1 ppm. In the argon atmosphere with a water content and an oxygen content both ≤ 0.1 ppm, coat the electrolyte slurry in step (1) on the surface of the lithium metal sheet at a coating amount of 80 μL cm -2 , and perform coating according to the coating process shown, and after uniform coating, let the tetrahydrofuran volatilize at 25 °C for 48 h to obtain a lithium metal anode - electrolyte integrated material. Figure 1 Using sulfur as the positive electrode active material, using the above - prepared lithium metal anode - electrolyte integrated material as the negative electrode and electrolyte, assemble the positive electrode, gasket, spring piece, and battery case in sequence to obtain a lithium metal solid - state battery.

[0077] Using sulfur as the positive electrode active material, using the above - prepared lithium metal anode - electrolyte integrated material as the negative electrode and electrolyte, assemble the positive electrode, gasket, spring piece, and battery case in sequence to obtain a lithium metal solid - state battery.

[0078] Example 6

[0079] A preparation method of a lithium metal anode - electrolyte integrated material, comprising the following steps:

[0080] (1) Weigh 0.4 g of dried LiTFSI, dissolve it in 9 g of tetrahydrofuran and stir at 25 °C for 12 h. After the electrolyte salt is completely dissolved, a uniform electrolyte salt solution is obtained; weigh 0.85 g of dried PVDC powder and 0.15 g of dried titanium dioxide powder (TiO2), add it to the prepared uniform electrolyte salt solution, and stir at 25 °C for 12 h to form a PVDC - TiO2 - LiTFSI electrolyte slurry.

[0081] (2) Transfer the uniformly dissolved or dispersed electrolyte slurry in step (1) to an argon atmosphere with a water content and an oxygen content both ≤ 0.1 ppm. In the argon atmosphere with a water content and an oxygen content both ≤ 0.1 ppm, coat the electrolyte slurry in step (1) on the surface of the lithium metal sheet at a coating amount of 60 μL cm -2 , and perform coating according to the coating process shown,Figure 1 The coating is carried out by the coating process shown in the figure. After the coating is uniformly applied, tetrahydrofuran is volatilized at 25° C. for 48 hours to obtain a lithium metal negative electrode-electrolyte integrated material.

[0082] Air is used as the positive electrode active material, the lithium metal negative electrode-electrolyte integrated material prepared above is used as the negative electrode and electrolyte, and the positive electrode, gasket, spring sheet, and battery shell are assembled in sequence to obtain a lithium metal solid-state battery.

[0083] Example 7

[0084] A method for preparing a sodium metal negative electrode-electrolyte integrated material comprises the following steps:

[0085] (1) Weigh 0.4 g of dried NaHCO3, dissolve it in 9 g of tetrahydrofuran, and stir at 25° C. for 12 h to obtain a uniform electrolyte salt solution after the electrolyte salt is completely dissolved; weigh 1 g of dried PVDC powder, add it to the prepared uniform electrolyte salt solution, and stir at 25° C. for 12 h to form a PVDC-NaHCO3 electrolyte slurry.

[0086] (2) The electrolyte slurry uniformly dissolved or dispersed in step (1) is transferred to an argon atmosphere with a water value and an oxygen value of ≤0.1 ppm. In the argon atmosphere with a water value and an oxygen value of ≤0.1 ppm, a 60 μL cm -2 The electrolyte slurry described in step (1) is applied to the surface of the metal sodium sheet in an amount of Figure 1 The coating is carried out by the coating process shown in the figure. After the coating is uniformly applied, tetrahydrofuran is volatilized at 25° C. for 48 hours to obtain a sodium metal negative electrode-electrolyte integrated material.

[0087] Ternary material NaNi 0.8 Co 0.1 Mn 0.1 O2 is the positive electrode active material, the sodium metal negative electrode-electrolyte integrated material prepared above is used as the negative electrode and electrolyte, and the positive electrode, gasket, spring sheet, and battery shell are assembled in sequence to obtain a sodium metal solid-state battery.

[0088] Example 8

[0089] A method for preparing a potassium metal anode-electrolyte integrated material comprises the following steps:

[0090] (1) Weigh 0.4 g of dried KTFSI, dissolve it in 9 g of tetrahydrofuran and stir it at 25° C. for 12 h to obtain a uniform electrolyte salt solution after the electrolyte salt is completely dissolved; weigh 1 g of dried PVDC powder, add it to the prepared uniform electrolyte salt solution, and stir it at 25° C. for 12 h to form an electrolyte slurry of PVDC-KTFSI.

[0091] (2) Transfer the uniformly dissolved or dispersed electrolyte slurry described in step (1) to an argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm. In the argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm, coat the electrolyte slurry described in step (1) on the surface of a potassium metal sheet at a coating amount of 60 μL / cm -2 . Perform coating according to the coating process as shown, and after the coating is uniform, allow tetrahydrofuran to volatilize at 25 °C for 48 h to obtain a potassium metal anode - electrolyte integrated material. Figure 1

[0092] Using a ternary material K 0.67 Ni 0.17 Co 0.17 Mn 0.66 O2 as the cathode active material, using the sodium metal anode - electrolyte integrated material prepared above as the anode and electrolyte, assemble the cathode, gasket, spring sheet, and battery case in sequence to obtain a potassium metal solid - state battery.

[0093] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent substitution methods and are all included in the protection scope of the present invention.

Claims

1. A solid-state battery assembled in air and based on an integrated alkali metal anode - electrolyte, characterized in that: The solid-state battery comprises a positive electrode and an alkali metal negative electrode-electrolyte integrated material, wherein the positive electrode faces the electrolyte side of the alkali metal negative electrode-electrolyte integrated material; the solid-state battery is assembled in an air environment in the order of a negative electrode shell, an alkali metal negative electrode-electrolyte integrated material, a positive electrode, a gasket, a spring sheet and a positive electrode shell; the alkali metal negative electrode-electrolyte integrated material is prepared according to the following preparation method: (1) dissolving the dried electrolyte salt in an organic solvent to obtain a uniform electrolyte salt solution; (2) adding polyvinylidene chloride (PVDC), an ion conductor component, to the electrolyte salt solution obtained in step (1), and fully stirring and dispersing the mixture to form a uniform electrolyte slurry; the process conditions for fully stirring and dispersing the mixture are: magnetic stirring at 20-30° C. for 2-12 h, followed by ultrasonic dispersion at 25-35° C. for 30 min to obtain a uniform electrolyte slurry; (3) The electrolyte slurry is coated on the surface of the alkali metal material in a protective atmosphere, and the alkali metal negative electrode-electrolyte integrated material is obtained after the organic solvent evaporates.

2. The solid-state battery based on an integrated alkali metal anode - electrolyte assembled in air according to claim 1, wherein: The electrolyte salt in step (1) is one or more of lithium perchlorate, lithium tetrafluoroborate, lithium hexafluoroarsenate, lithium hexafluorophosphate, lithium bis(oxalatoborate), lithium difluorooxalatoborate, lithium bis(difluorosulfonylimide), lithium bis(trifluoromethylsulfonylimide), sodium bicarbonate, sodium carbonate, sodium chloride, sodium thiocarbonate, sodium sulfate, sodium nitrate, sodium fluoride, potassium fluoroborate, potassium hexafluorophosphate, potassium bis(fluorosulfonylimide), potassium bis(trifluoromethylsulfonylimide), potassium perchlorate and potassium trifluoromethanesulfonate; The organic solvent is one or more of tetrahydrofuran, N-methylpyrrolidone, cyclohexanone and N,N-dimethylformamide.

3. A solid-state battery assembled in air and based on an integrated alkali metal anode - electrolyte, as claimed in claim 2, wherein: The ionic conductor composition further contains an additive, and the content of the additive is 0-20 wt%; the additive is one or more of an organic polymer and an inorganic nanoparticle; the organic polymer is polyacrylonitrile, polymethyl methacrylate, and polyethylene oxide, and the inorganic nanoparticle is one or more of silicon dioxide, zirconia, titanium dioxide, Li7La3Zr2O 12 , Li 6.4 La3Zr 1.4 Ta 0.6 O 12 , Li 10 GeP2S 12 and one or more of Li6PS5Cl.

4. A solid-state battery assembled in air and based on an integrated alkali metal anode - electrolyte, characterized in that: In step (2), the content of the ion conductor component in the electrolyte slurry is 0-60wt%, and the content of the electrolyte salt component is 5-80wt%.

5. A solid-state battery assembled in air and based on an integrated alkali metal anode - electrolyte, characterized in that: The alkali metal material in step (3) is one of lithium sheet, sodium sheet, potassium sheet, lithium alloy, sodium alloy and potassium alloy; The coating amount of the electrolyte slurry is 10 - 150 μL / cm 2 ; The protective atmosphere is specifically an argon atmosphere with a water value and an oxygen value both ≤ 0.1 ppm; The process conditions for volatilizing the organic solvent are: in an argon atmosphere with a water value and an oxygen value of ≤0.1 ppm, the temperature is maintained at 20-30° C., and the organic solvent is naturally volatilized for 12-72 hours under a protective atmosphere.

6. The solid-state battery based on an integrated alkali metal anode - electrolyte assembled in air according to claim 1, wherein: The thickness of the electrolyte membrane in the alkali metal negative electrode-electrolyte integrated material is 5 μm to 150 μm, the content of the ion conductor in the electrolyte membrane is 55-96 wt %, and the content of the electrolyte salt is 4-45 wt %.

7. A solid-state battery assembled in air and based on an integrated alkali metal anode-electrolyte, characterized in that: The active material of the positive electrode is air, sulfur, sulfur / carbon composite or composite metal oxide; the composite metal oxide is Li w Ni x Co y Mn z A (1-x-y-z) O2, LiCo x A (1-x) O2, LiFexA (1-x) PO4, Na w Ni x Co y Mn z A (1-x-y-z) O2, NaCo x A (1-x) O2, NaFe x A (1-x) PO4, K w Ni x Co y Mn z A (1-x-y-z) O2, KCo x A (1-x) O2 and KFe x A (1-x) PO4, where A is Al, Sr, Mg, Ti, Ca, Zr, Zn, Si or Fe, 0 ≤ x ≤ 1, 0 ≤ y ≤ 1, 0 ≤ z ≤ 1, 0 ≤ w ≤ 2.

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