A solid-state battery modified with an ion / electron mixed-conducting solid-state interface layer and a preparation method thereof

Abstract

The present invention discloses a solid-state battery modified with an ion / electron mixed-conducting solid-state interfacial layer and a preparation method thereof, which includes a solid electrolyte, and an ion / electron mixed-conducting solid-state interfacial layer is modified on the surface of the solid electrolyte. The material of the ion / electron mixed-conducting solid-state interfacial layer has a solvated electron structure. The interfacial construction method of the solid electrolyte provided by the present invention is applicable to rechargeable solid-state battery systems. By constructing an ion / electron mixed-conducting solid-state interfacial layer on the surface of the solid electrolyte, the interfacial resistance of the solid-state battery can be effectively reduced, and at the same time, the distribution of the electric field on the interface can be regulated to regulate the nucleation and growth of lithium, sodium or potassium. Therefore, the cycle stability of the battery can be improved, thereby extending the service life of the large-capacity rechargeable battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of rechargeable batteries, and particularly relates to a solid-state battery modified with an ion / electron hybrid conductive solid-state interface layer and a preparation method thereof. Background Art

[0002] With the development of new fields such as new energy vehicles and 5G communications, the development of rechargeable batteries with high energy density, high power density and long cycle life has become an important research direction. Traditional rechargeable batteries are based on highly flammable organic solvents, and under conditions such as high temperature, overcharge or external collision, phenomena such as internal short circuit and thermal runaway of the battery may be triggered, and even safety accidents such as battery explosion may occur. In recent years, solid electrolytes have become the focus of research due to their high safety characteristics. With the in-depth research on preparation processes and material structure regulation methods, the room-temperature ionic conductivity of solid electrolytes has reached 10 -3 S / cm or more. It has good flame retardancy, and its large electrochemical window enables it to match high-voltage cathodes, which helps to obtain safe and high-energy-density solid-state batteries. The above advantages make solid electrolytes and related solid-state batteries the focus and hotspots of research. Nevertheless, the large interfacial resistance between solid electrolytes and lithium metal is still a huge challenge restricting their use. The "point contact" between lithium metal and solid electrolyte will induce lithium to nucleate preferentially at certain sites. Once dendrites start to grow, the electric field at the interface will change. Lithium ions will preferentially deposit on the existing dendrites and then gradually expand into grain boundaries, pores and defects in the solid electrolyte, eventually leading to short circuit. This problem also exists for sodium metal batteries and potassium metal batteries. Therefore, it is very important to reduce the interfacial resistance and regulate the distribution of the electric field at the interface to regulate the nucleation and growth of lithium, sodium and potassium.

[0003] To address the above problems, introducing a lithiophilic interfacial layer between the solid electrolyte and the lithium metal is an effective method. For example, modifying the surface of the solid electrolyte with Al2O3, ZnO, etc. through atomic layer vapor deposition (ALD) can promote the close contact between this interfacial layer and molten lithium, improving the wettability of the interface (Nature Materials, 2017, 16(5):572, ACS Energy Lett. 2020, 5, 2156-2164). In the liquid electrolyte system, a good solid electrolyte interface layer (SEI) needs to simultaneously satisfy high ionic conductivity and low electronic conductivity to ensure the effective transport of ions between the electrode and the electrolyte interface and inhibit the occurrence of side reactions (ACS Energy Lett., 2018, 3, 1564–1570). Drawing on this experience, a fullerene interface with low electronic conductivity is deposited on the surface of the solid electrolyte by vacuum evaporation. This interface effectively inhibits side reactions at the interface, thus greatly improving the cycle stability of the battery (Patent: CN 111224048 A). However, in the case of "solid-solid contact" in the solid-state battery system, even if the requirements of high ionic conductivity and low electronic conductivity are met, the interfacial resistance of the battery is still relatively large (Rare Met., 2018, 37, 473–479). Based on this, the magnetron sputtering method is used to introduce a Cu3N interfacial layer between the electrode and the electrolyte. The in-situ reaction of Cu3N with lithium yields ion-conducting Li3N and conductive Cu nanoparticles, greatly reducing the interfacial resistance and effectively inhibiting the growth of dendrites (Energy Environ. Sci., 2020, 13, 127-134). On the other hand, converting solid-solid contact to solid-liquid contact has also been reported. Researchers modified the solid electrolyte with metals such as liquid Ga and Ga / In / Sn alloys at room temperature (Nature Communications, 2020, 11(1):3716. Patent: CN 110518278), and when matched with lithium metal, it can also improve the contact problem between the electrolyte and the electrode.

[0004] However, the above methods involve complex preparation techniques, or the use of energy-consuming instruments, or the use of relatively heavy metals or alloy layers, which is not conducive to obtaining high-energy-density batteries. Summary of the Invention

[0005] Aiming at the deficiencies of the above-mentioned existing technologies, the present invention provides a solid-state battery modified with an ion / electron mixed-conducting solid-state interface layer, and the technical problem to be solved is: to form an ion / electron mixed-conducting solid-state interface layer on the surface of the solid electrolyte by using a material with a solvated electron structure, so as to promote the contact between interfaces and homogenize the distribution of the interface electric field, thereby improving the cycle stability of the battery and effectively extending the service life of the large-capacity rechargeable solid-state battery.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A solid-state battery modified with an ion / electron mixed-conducting solid-state interface layer, characterized in that: it includes a solid electrolyte, and an ion / electron mixed-conducting solid-state interface layer is modified on the surface of the solid electrolyte, and the material of the ion / electron mixed-conducting solid-state interface layer has a solvated electron structure.

[0008] Furthermore, the solid-state battery is a solid-state lithium metal battery, a solid-state sodium metal battery or a solid-state potassium metal battery. When the solid-state battery is a solid-state lithium metal battery, the material of the ion / electron mixed-conducting solid-state interface layer includes an aryllithium material; when the solid-state battery is a solid-state sodium metal battery, the material of the ion / electron mixed-conducting solid-state interface layer includes an arylsodium material; when the solid-state battery is a solid-state potassium metal battery, the material of the ion / electron mixed-conducting solid-state interface layer includes an arylpotassium material.

[0009] Even further, the aryllithium material is at least one of lithium naphthalide, lithium biphenyl, lithium anthracene and their derivatives, the arylsodium material is at least one of sodium naphthalide, sodium biphenyl, sodium anthracene and their derivatives, and the arylpotassium material is at least one of potassium naphthalide, potassium biphenyl, potassium anthracene and their derivatives.

[0010] Furthermore, the solid electrolyte is an oxide solid electrolyte (such as LLZTO, LiPON, Garnet, LAGP, NASICON, Peorvskite or Anti-Peorvskite, etc.), a sulfide solid electrolyte (such as LGPS or LPS, etc.), a halide solid electrolyte or an organic-inorganic composite solid electrolyte (such as PEO-LLZTO, etc.).

[0011] The preparation method of the solid-state battery modified with an ion / electron mixed-conducting solid-state interface layer according to the present invention is as follows: dissolve an aromatic ring compound, lithium, sodium or potassium in a solvent and stir to react to obtain a corresponding solution of aryllithium, arylsodium or arylpotassium; then soak a solid electrolyte in the obtained solution, take it out and dry to remove the excess solvent, and an ion / electron mixed-conducting solid-state interface layer is modified on the surface of the solid electrolyte; assemble the solid electrolyte with a surface-modified ion / electron mixed-conducting solid-state interface layer and an electrode to obtain a solid-state battery.

[0012] Further, the aromatic ring compound is at least one of naphthalene, biphenyl, anthracene and their derivatives, and its structural formula is as Figure 1 shown.

[0013] Further: when the metal is lithium, the solvent is an ether solvent; when the metal is sodium or potassium, the solvent is an ether solvent or liquid ammonia. More specifically, the ether solvent is one or several of solvents such as ethylene glycol dimethyl ether, tetrahydrofuran or dimethyltetrahydrofuran. When using an ether as the solvent of the aromatic ring compound, lithium / sodium / potassium is more easily dissolved and forms a solvated electron structure. And sodium and potassium can also form a solvated electron structure in liquid ammonia.

[0014] Further, the molar ratio of the aromatic ring compound to lithium, sodium or potassium metal is 0.2-5:1. Taking lithium naphthalide as an example, the formed solvated electron structure is as shown in the following formula, where the molar ratio of the aromatic ring to lithium is 1:1:

[0015]

[0016] Further, the assembly method of the solid-state battery of the present invention is a conventional method well known in the art. For example, in the examples of the present invention, a 2032 button cell is used for assembly and testing comparison, and the assembly order is: negative electrode case - 1 mm stainless steel gasket - lithium sheet with a diameter of 10 mm - solid electrolyte - lithium sheet with a diameter of 10 mm - positive electrode case. When preparing a solid-state sodium metal battery or a solid-state potassium metal battery, the solid electrolyte is a corresponding sodium / potassium-containing solid electrolyte, and the electrode is sodium or potassium.

[0017] Generally, the "solvated electron" structure refers to the existence of a free electron structure in a solution. Solvated electron structures can be generated in many systems, but common solvated electrons are often unstable. In the present invention, an aryl compound with a conjugated structure is used to generate solvated electrons, improving the stability of the solvated electrons and providing the possibility of constructing solvated electrons at the electrolyte interface. It can also be seen from the solvated electron structure of lithium naphthalide that in order to maintain charge balance, free electrons are always paired with corresponding alkali metal ions, so an ion / electron mixed-conducting solid-state interface layer can be obtained on the electrolyte surface. And the lithium-rich structure can promote Li +conduction to further improve Li + migration and diffusion kinetics. The electron-rich structure can promote the uniform distribution of the electric field, further induce the uniform deposition of electrons on the interface, and then induce the uniform deposition of lithium. Therefore, introducing an interfacial layer with excellent Li + ionic conductivity and high electronic conductivity significantly increases the cycle stability of solid-state lithium metal batteries. Due to the inherent similarity between solid-state alkali metal batteries, the ion / electron mixed-conducting solid-state interfacial layer in the present invention is also applicable to solid-state sodium metal batteries and solid-state potassium metal batteries.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. The method for constructing the interface of the solid electrolyte provided by the present invention is applicable to rechargeable solid battery systems. By constructing an ion / electron mixed-conducting solid-state interfacial layer on the surface of the solid electrolyte, the interfacial resistance of the solid battery can be effectively reduced, and at the same time, the distribution of the electric field on the interface can be regulated to control the nucleation and growth of lithium, sodium or potassium. Therefore, the cycle stability of the battery can be improved, thereby extending the service life of high-capacity rechargeable lithium batteries.

[0020] 2. The raw materials used in the present invention are cheap and easily available, and a thin and stable interface is constructed on the solid electrolyte by a simple process, which is conducive to commercial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of some aromatic ring compounds used in the present invention.

[0022] Figure 2 (a) and (b) are the galvanostatic cycling performance graphs of the Li / Li symmetric battery assembled with LLZTO modified with lithium naphthalide and the blank control Li / Li symmetric battery assembled with unmodified LLZTO in Example 1 at 25 °C and 0.1 mA cm -2 under (0.1 mA h cm -2 ); Figure 2 (c) and (d) are the galvanostatic cycling performance graphs of the Li / Li symmetric battery assembled with LLZTO modified with lithium naphthalide and the blank control Li / Li symmetric battery assembled with unmodified LLZTO in Example 1 at 65 °C and 0.2 mA cm -2 under (0.2 mA h cm -2 );

[0023] Figure 3 is the SEM image of the sample in Example 1, where: Figure 3 (a) represents blank LLZTO, Figure 3 (b) represents the sample after cycling for 100 h (65 °C, 0.2 mA cm -2LLZTO modified with lithium naphthalenide after Figure 3 (c) represents LLZTO after short circuit (the inset is an enlarged view), Figure 3 (d) and (e) respectively represent the SEM images of the lithium side of Li / LLZTO / Li after short circuit and Li / lithium naphthalenide@LLZTO / Li after 100 h of cycling (65 °C, 0.2 mA cm -2 ).

[0024] Figure 4 Electron paramagnetic resonance data graph of lithium naphthalenide prepared in Example 1, where (a) is liquid lithium naphthalenide and (b) is solid lithium naphthalenide after vacuum drying at room temperature for 15 minutes.

[0025] Figure 5 For the Li / Li symmetric battery assembled with LLZTO modified with lithium biphenyl in Example 2 at 65 °C, 0.2 mA cm -2 under the galvanostatic cycling performance graph (0.2 mA h cm -2 ).

[0026] Figure 6 (a) and (b) are respectively the galvanostatic cycling performance graphs (0.025 mA h cm -2 ) of the Na / Na symmetric battery assembled with NZSP modified with sodium naphthalenide and the blank control Na / Na symmetric battery assembled with unmodified NZSP in Example 4 at 25 °C, 0.05 mA cm -2 . Detailed implementation manners

[0027] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0028] Example 1

[0029] This example prepares a rechargeable solid-state lithium-ion battery according to the following steps:

[0030] Step 1): Press the solid electrolyte Li 6.4 La3Zr 1.4 Ta 1.6 O 12 (purity ≥ 99.99%, particle size 15 μm) powder into a sheet with a diameter of about 13 mm and a thickness of about 1 mm, and place it in a muffle furnace to sinter into an LLZTO ceramic sheet with a diameter of 11 mm for standby.

[0031] Step 2): Configure 1 mol L -1Naphthalene lithium solution: Dissolve 1.28 g of naphthalene (10 mmol) in 10 mL of 1,2-dimethoxyethane, and then dissolve 69.4 mg of lithium chips (10 mmol) in the above solution. Stir for 40 minutes at room temperature to obtain the naphthalene lithium solution. This operation is completed in a glove box filled with argon with a water value and an oxygen value both less than 0.1 ppm.

[0032] Step 3): Immerse the LLZTO ceramic sheet in the naphthalene lithium solution for 5 minutes, then take it out and dry it in vacuum at room temperature for 15 minutes to obtain the solid electrolyte coated with naphthalene lithium.

[0033] Step 4): Assemble the naphthalene lithium-modified LLZTO obtained above into a CR2032 coin cell in a glove box filled with argon. The assembly sequence is: negative electrode case - stainless steel gasket - lithium sheet with a diameter of 10 mm - naphthalene lithium@LLZTO - lithium sheet with a diameter of 10 mm - positive electrode case. Correspondingly, Li / LLZTO / Li is assembled using unmodified naphthalene lithium LLZTO as a blank control group.

[0034] To confirm that naphthalene lithium has solvated electron characteristics both in liquid and solid states, vacuum dry naphthalene lithium for 15 minutes and detect its electron paramagnetic resonance signals in liquid and solid states.

[0035] Figure 2 (a), (b) are the galvanostatic cycling performance graphs (0.1 mAh cm -2 ) of the Li / Li symmetric cell assembled with naphthalene lithium-modified LLZTO and the blank control Li / Li symmetric cell assembled with unmodified naphthalene lithium LLZTO at 25 °C and 0.1 mA cm -2 . As shown in the figure, the Li / Li symmetric cell assembled with naphthalene lithium-modified LLZTO exhibits a stable overpotential plateau of about 52 mV and can be stably cycled for more than 950 h. While the blank LLZTO has an inclined deposition / stripping curve at the beginning and the overpotential rises to more than 0.5 V, showing non-uniform lithium deposition and stripping behavior, and short circuit occurs after 1 cycle, because the poor LLZTO / Li contact leads to non-uniform current distribution and local Li + current is generated at the defects of the electrolyte, resulting in dendrite growth.

[0036] Further increase the temperature to 65 °C, Figure 2 (c), (d) are the galvanostatic cycling performance graphs (0.2 mA h cm -2 ) of the Li / Li symmetric cell assembled with naphthalene lithium-modified LLZTO and the blank control Li / Li symmetric cell assembled with unmodified naphthalene lithium LLZTO at 65 °C and 0.2 mA cm -2)。It can be clearly observed that after the temperature increases, the overpotential during the charge and discharge process also significantly decreases because the ionic conductivity of the solid electrolyte increases. In addition, the battery with LLZTO modified with naphthyllithium can stably cycle for 1200 h and maintain the overpotential at 12 mV without obvious increase. The overpotential of the Li / LLZTO / Li symmetric battery is 120 mV, and short circuit occurs after 4 weeks of cycling.

[0037] Disassemble the Li / Li symmetric battery assembled with LLZTO modified with naphthyllithium and cycled for 100 h (65 °C, 0.2 mA cm -2 ), conduct SEM testing on it, and use the short-circuited Li / LLZTO / Li and the blank LLZTO ceramic sheet as blank control experiments. The test results are as Figure 3 shown, where Figure 3 (a) represents the blank LLZTO, Figure 3 (b) represents the LLZTO modified with naphthyllithium, Figure 3 (c) represents the LLZTO after short circuit (the inset is an enlarged view). The SEM test results show that after the LLZTO modified with naphthyllithium cycles for 100 h, its morphology is the same as that of the blank LLZTO ceramic sheet, and no obvious lithium dendrites are observed. However, obvious lithium dendrites can be observed after disassembling the short-circuited LLZTO, further proving the inhibitory effect of the ion / electron mixed conductive layer on lithium dendrites. Figure 3 (d) and (e) respectively represent the SEM images of the lithium side of Li / LLZTO / Li and Li / naphthyllithium@LLZTO / Li. This data shows that the lithium deposition morphology of the battery modified with naphthyllithium is denser, corresponding to the results observed by SEM on the LLZTO side above.

[0038] To further illustrate that the naphthyllithium after vacuum drying still has electronic properties, electron paramagnetic resonance (EPR) testing is carried out on liquid naphthyllithium and naphthyllithium vacuum dried for 15 minutes. Figure 4 (a) is the EPR of liquid naphthyllithium, showing a strong EPR signal, indicating the existence of free radical compounds. Figure 4 (b) is the EPR of vacuum dried for 15 minutes. Since it is in a solid state at this time, the intermolecular force becomes stronger, and the fine structure of the naphthyllithium radical cannot be observed, but a strong free radical signal can still be observed, indicating that there is still a solvated electron structure in the solid state. The existence of the solvated electron layer can homogenize the electric field distribution at the interface, thereby improving the cycle stability of the battery, which is consistent with the above experimental results.

[0039] Example 2

[0040] This example prepares a rechargeable solid-state lithium-ion battery according to the following steps:

[0041] Step 1): Press the solid electrolyte Li 6.4 La3Zr 1.4 Ta 1.6 O 12 (with a purity of ≥99.99%, particle size of 15 μm) powder into a tablet with a diameter of about 13 mm and a thickness of about 1 mm, and place it in a muffle furnace to sinter into an LLZTO ceramic tablet with a diameter of 11 mm for standby.

[0042] Step 2): Prepare a 1 mol L -1 solution of lithium biphenyl: Dissolve 1.54 g of biphenyl (10 mmol) in 10 mL of ethylene glycol dimethyl ether, and then dissolve 69.4 mg of lithium sheet (10 mmol) in the above solution, and stir at room temperature for 40 minutes to obtain a lithium biphenyl solution. This operation is completed in a glove box filled with argon with a water value and an oxygen value of less than 0.1 ppm.

[0043] Step 3): Place the LLZTO ceramic tablet in the lithium biphenyl solution, soak it for 5 minutes, then take it out and dry it in vacuum at room temperature for 15 minutes to obtain a solid electrolyte coated with lithium biphenyl.

[0044] Step 4): Assemble the above-obtained lithium biphenyl-modified LLZTO into a CR2032 coin-type battery in a glove box filled with argon. The assembly sequence is: negative electrode case - stainless steel gasket - lithium sheet with a diameter of 10 mm - lithium biphenyl@LLZTO - lithium sheet with a diameter of 10 mm - positive electrode case.

[0045] Figure 5 is the constant current cycling performance graph (0.2 mA h cm -2 ) of the Li / Li symmetric battery assembled with LLZTO modified with lithium biphenyl at 65 °C and 0.2 mA cm -2 . It can be seen from the figure that the battery assembled with LLZTO modified with lithium biphenyl shows a lower and flatter charge-discharge overpotential of 15 mV, indicating that lithium biphenyl modification of LLZTO can significantly improve the battery performance.

[0046] Example 3

[0047] This example prepares a rechargeable solid-state lithium-ion battery according to the following steps:

[0048] Step 1): Press the solid electrolyte Li 6.4 La3Zr 1.4 Ta 1.6 O 12 (with a purity of ≥99.99%, particle size of 15 μm) powder into a tablet with a diameter of about 13 mm and a thickness of about 1 mm, and place it in a muffle furnace to sinter into an LLZTO ceramic tablet with a diameter of 11 mm for standby.

[0049] Step 2): Prepare 1 mol L -1 anthracene-lithium solution: Dissolve 1.79 g of anthracene (10 mmol) in 10 mL of dimethoxyethane, and then dissolve 69.4 mg of lithium flakes (10 mmol) in the above solution. Stir for 40 minutes at room temperature to obtain the anthracene-lithium solution. This operation is completed in a glove box filled with argon with a water content and an oxygen content both less than 0.1 ppm.

[0050] Step 3): Place the LLZTO ceramic sheet in the anthracene-lithium solution, soak for 5 minutes, then take it out and vacuum dry at room temperature for 15 minutes to obtain a solid electrolyte coated with anthracene-lithium.

[0051] Step 4): Assemble the anthracene-lithium modified LLZTO obtained above into a CR2032 coin-type battery in a glove box filled with argon. The assembly order is: negative electrode case - stainless steel gasket - lithium sheet with a diameter of 10 mm - anthracene-lithium@LLZTO - lithium sheet with a diameter of 10 mm - positive electrode case. Correspondingly, assemble Li / LLZTO / Li using unmodified anthracene-lithium LLZTO as a blank control group.

[0052] Perform a cyclic stability test on the Li / LLZTO / Li and Li / anthracene-lithium@LLZTO / Li symmetric batteries assembled in this example. The results show that the battery assembled with anthracene-lithium modified LLZTO exhibits a lower and flatter charge-discharge overpotential and has good cyclic stability.

[0053] Example 4

[0054] Prepare a rechargeable solid-state sodium-ion battery according to the following steps in this example:

[0055] Step 1): Prepare 1 mol L -1 sodium naphthalide solution: Dissolve 1.28 g of naphthalene (10 mmol) in 10 mL of dimethoxyethane, and then dissolve 230 mg of sodium (10 mmol) in the above solution. Stir for 40 minutes at room temperature to obtain the sodium naphthalide solution. This operation is completed in a glove box filled with argon with a water content and an oxygen content both less than 0.1 ppm.

[0056] Step 2): Place the Na3Zr2Si2PO 12 (NZSP) ceramic sheet in the sodium naphthalide solution, soak for 5 minutes, then take it out and vacuum dry at room temperature for 15 minutes to obtain a solid electrolyte coated with sodium naphthalide.

[0057] Step 3): Assemble the sodium naphthalide modified NZSP obtained above into a CR2032 coin-type battery in a glove box filled with argon. The assembly order is: negative electrode case - stainless steel gasket - sodium - sodium naphthalide@NZSP - sodium - positive electrode case. Correspondingly, assemble Na / NZSP / Na using unmodified sodium naphthalide NZSP as a blank control group.

[0058] Figure 6 (a) and (b) are the galvanostatic cycling performance graphs of the Na / Na symmetric battery assembled with NZSP modified by sodium naphthalide and the blank control Na / Na symmetric battery assembled with NZSP without sodium naphthalide modification at 25 °C and 0.05 mA cm -2 under (0.025 mAh cm -2 ). It can be seen that the battery assembled with NZSP modified by sodium naphthalide can stably cycle for more than 30 hours, while the NZSP without sodium naphthalide modification cannot cycle due to excessive interfacial resistance, indicating that sodium naphthalide modification of NZSP can significantly improve the battery performance.

[0059] Obviously, the above specific embodiments are only examples for clearly explaining the present invention, rather than limiting the scope of use of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A solid-state battery modified with an ion / electron mixed-conducting solid-state interfacial layer, characterized in that: It includes a solid electrolyte, and a solid interfacial layer with mixed ionic / electronic conductivity is modified on the surface of the solid electrolyte. The material of the solid interfacial layer with mixed ionic / electronic conductivity has a solvated electron structure; the solid electrolyte is an oxide solid electrolyte, a sulfide solid electrolyte, a halide solid electrolyte, or an organic-inorganic composite solid electrolyte; The solid-state battery is a solid-state lithium metal battery, a solid-state sodium metal battery, or a solid-state potassium metal battery; When the solid-state battery is a solid-state lithium metal battery, the material of the solid interfacial layer with mixed ionic / electronic conductivity contains an aryllithium material; When the solid-state battery is a solid-state sodium metal battery, the material of the solid interfacial layer with mixed ionic / electronic conductivity contains an arylsodium material; When the solid-state battery is a solid-state potassium metal battery, the material of the solid interfacial layer with mixed ionic / electronic conductivity contains an arylpotassium material.

2. A solid-state battery modified with a solid interfacial layer with mixed ionic / electronic conductivity according to claim 1, wherein: The aryllithium material is at least one of lithium naphthalide, lithium biphenyl, lithium anthracene, and their derivatives; The arylsodium material is at least one of sodium naphthalide, sodium biphenyl, sodium anthracene, and their derivatives; The arylpotassium material is at least one of potassium naphthalide, potassium biphenyl, potassium anthracene, and their derivatives.

3. A method for preparing a solid-state battery modified with an ion / electron mixed-conducting solid-state interface layer according to any one of claims 1 to 2, characterized in that: Dissolve an aromatic ring compound and lithium, sodium, or potassium metal in a solvent and stir to react to obtain a corresponding solution of aryllithium, arylsodium, or arylpotassium; then immerse the solid electrolyte in the obtained solution, take it out and dry to remove the excess solvent, and a solid interfacial layer with mixed ionic / electronic conductivity is modified on the surface of the solid electrolyte; assemble the solid electrolyte with a surface modified with a solid interfacial layer with mixed ionic / electronic conductivity and an electrode to obtain a solid-state battery.

4. The preparation method according to claim 3, characterized in that: The aromatic ring compound is at least one of naphthalene, biphenyl, anthracene, and their derivatives.

5. The preparation method according to claim 3, characterized in that: When the metal is lithium, the solvent is an ether solvent; when the metal is sodium or potassium, the solvent is an ether solvent or liquid ammonia.

6. The preparation method according to claim 5, characterized in that: The ether solvent is at least one of ethylene glycol dimethyl ether, tetrahydrofuran, and dimethyltetrahydrofuran.

7. The preparation method according to claim 3, characterized in that: The molar ratio of the aromatic ring compound to lithium, sodium, or potassium metal is 0.2~5:1.

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