Electrolyte for inhibiting dendritic crystal growth of solid-state lithium metal battery and preparation process of electrolyte

Abstract

The invention discloses an electrolyte for inhibiting dendritic crystal growth of a solid-state lithium metal battery and a preparation process of the electrolyte, and relates to the field of solid-state battery electrolyte preparation. The solid electrolyte material is formed by compounding inorganic and organic components, has high ionic conductivity, and can effectively prevent lithium dendrites from penetrating the electrolyte. The preparation process comprises the steps of solid-phase synthesis and heat treatment, so that the electrolyte is compact in structure and stable in interface, and the cycle life and safety of the lithium metal battery can be improved. The solid electrolyte material can be widely applied to the field of high-energy-density solid lithium metal batteries.

Description

Technical Field

[0001] The present invention relates to the field of solid-state battery electrolyte preparation, in particular to an electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and a preparation process thereof. Background Art

[0002] Lithium metal batteries are considered to be a strong candidate for the next generation of high energy density energy storage devices. Due to their ultra-high theoretical energy density and low potential advantages, they have become an important part of promoting technological progress in the fields of electric vehicles, renewable energy storage, and portable electronic devices. Compared with traditional lithium-ion batteries, the negative electrode material in lithium metal batteries is metallic lithium, and the theoretical capacity can reach 3860mAh / g, which is much higher than the graphite negative electrode (372mAh / g). However, despite the many advantages of lithium metal batteries, they face many challenges in the process of commercialization, the most prominent of which is the growth of lithium dendrites.

[0003] Lithium dendrites refer to the uneven deposition of lithium ions on the surface of the metal lithium negative electrode during the battery charging and discharging process, resulting in the formation of branched or dendritic metal structures. These dendrites may penetrate the battery's separator or electrolyte layer, eventually causing a short circuit between the positive and negative electrodes, leading to thermal runaway of the battery, and even causing serious safety accidents such as explosions. In addition, the formation of lithium dendrites will also lead to the uneven deposition of lithium metal, reducing the coulombic efficiency and cycle life of the battery. Therefore, how to effectively inhibit the growth of lithium dendrites and improve the safety and stability of lithium metal batteries has become the current research focus in the field of lithium metal batteries.

[0004] The application of traditional liquid electrolytes in lithium metal batteries is widely used in the field of lithium-ion batteries due to its good ionic conductivity and easy wettability. However, in lithium metal batteries, the biggest problem facing liquid electrolytes is the difficulty in inhibiting the growth of lithium dendrites. Due to the low mechanical strength of liquid electrolytes, it is impossible to effectively prevent lithium dendrites from penetrating the electrolyte, which in turn causes a short circuit in the battery. Therefore, the application of liquid electrolytes in lithium metal batteries is greatly limited.

[0005] Solid electrolyte materials are considered to be an ideal solution to the lithium dendrite problem due to their high mechanical strength and good electrochemical stability. Solid electrolytes can not only act as lithium ion conductive media, but also as physical barriers to effectively inhibit the growth of lithium dendrites. However, existing solid electrolyte materials still face some challenges in practical applications:

[0006] 1) Low ionic conductivity: The ionic conductivity of most solid electrolyte materials is much lower than that of liquid electrolytes, especially the poor ionic conductivity at room temperature, which limits their application in high power density batteries.

[0007] 2) Poor interface stability: An unstable interface is easily formed between the solid electrolyte and the lithium metal negative electrode, resulting in an increase in interface resistance and a rapid decay of battery capacity due to chemical reactions at the interface. 3) Complex preparation process: The preparation process of some solid electrolyte materials is complex and costly, making it difficult to achieve large-scale production, limiting their promotion in practical applications.

[0008] In order to overcome these problems, researchers have been committed to developing composite solid electrolyte materials in recent years. Composite solid electrolytes combine inorganic solid electrolytes with organic polymers, combining the high mechanical strength of inorganic electrolytes with the flexibility and processability of organic polymers, which can effectively improve ionic conductivity and enhance interface stability. At the same time, composite solid electrolytes can also further improve the comprehensive performance of materials by adjusting the proportion of components and optimizing the preparation process, making them more suitable for the application of high energy density lithium metal batteries. Summary of the invention

[0009] The composite solid electrolyte material proposed in the present invention is based on the research background of the above-mentioned problems. It aims to provide a solid electrolyte material with high ionic conductivity, interface stability and mechanical strength through reasonable material design and process optimization, so as to solve the deficiencies in the prior art, inhibit the growth of lithium dendrites, extend the cycle life of the battery, and improve the overall safety of the battery.

[0010] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] An electrolyte for inhibiting dendrite growth of a solid-state lithium metal battery and a preparation process thereof, characterized in that the electrolyte comprises the following steps:

[0012] (1) 50-80 parts of inorganic electrolyte powder and 10-40 parts of organic polymer matrix are mixed uniformly by mass, and then 5-20 parts of lithium salt and 1-10 parts of interface enhancer are added, and ball milling is performed for 1-4 hours;

[0013] (2) hot pressing the mixture in a mold, and annealing the hot pressed electrolyte material to improve the density and ion conductivity of the material, thereby obtaining the electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries.

[0014] As a supplement to the above preparation method, the inorganic solid electrolyte material is Li7La3Zr2O 12 (LLZO), Li 10 GeP2S 12 (LGPS) or Li6PS5Cl.

[0015] As a supplement to the above preparation method, the organic polymer matrix is ​​at least one of polyethylene glycol (PEG), polyvinylidene fluoride (PVDF), polyurethane (PU) or polyethylene oxide (PEO), and its molecular weight ranges from 10,000 to 500,000.

[0016] As a supplement to the above preparation method, the lithium salt is at least one of LiTFSI (lithium bis(trifluoromethanesulfonyl)imide), LiClO4 or LiBF4.

[0017] As a supplement to the above preparation method, the interface enhancer is composed of the following components:

[0018] Fluoro-4-(pentafluorothio)aniline (CAS: 2993-24-0): 20-40 parts;

[0019] 2-[(Thiophen-2-ylmethoxy)methyl]ethylene oxide (CAS: 80910-06-1): 0.04-0.5 parts;

[0020] 1,4-Dimethyl-2-pyrrolidone (CAS: 2555-04-6): 1000-1400 parts;

[0021] Ethylenediamine (CAS: 107-15-3): 2-5 parts;

[0022] N-(3-aminopropyl)diethanolamine (CAS: 4985-85-7): 17-34 parts.

[0023] As a supplement to the above preparation method, the preparation method of the interface enhancer is:

[0024] According to the mass fractions, N-(3-aminopropyl)diethanolamine and 2-[(thiophen-2-ylmethoxy)methyl]ethylene oxide are added to 1,4-dimethyl-2-pyrrolidone, and ethylenediamine is added after stirring and mixing evenly, and then stirred and reacted at 60-80° C. for 50-100 minutes; then fluoro-4-(pentafluorothio)aniline is added and the temperature is controlled at 60-80° C., and the reaction is stirred for 100-120 minutes, and 1,4-dimethyl-2-pyrrolidone is distilled off to obtain the interface enhancer.

[0025] As a supplement to the above preparation method, the rotation speed of the ball milling treatment is 300-500rpm, and the ball-to-material ratio is 10:1-20:1.

[0026] As a supplement to the above preparation method, the hot pressing molding process: the hot pressing temperature is 80-120°C, the pressure is 10-50MPa, and the time is 4-8 hours.

[0027] As a supplement to the above preparation method, the heat treatment process: the annealing temperature is 100-150°C and the time is 2-6 hours.

[0028] Reaction mechanism of interface enhancer:

[0029] 1) The amino ring-opening reaction between fluoro-4-(pentafluorothio)aniline and 2-[(thiophen-2-ylmethoxy)methyl]oxirane may proceed via a nucleophilic addition or electron transfer mechanism. First, the amino group in fluoro-4-(pentafluorothio)aniline acts as a nucleophile to attack the epoxy group in 2-[(thiophen-2-ylmethoxy)methyl]oxirane, resulting in the cleavage of the epoxy bond and the formation of a new carbon-nitrogen bond, thereby achieving the ring-opening reaction of the amino group.

[0030] 2) The amino ring-opening reaction between N-(3-aminopropyl)diethanolamine and 2-[(thiophen-2-ylmethoxy)methyl]oxirane may also proceed through a nucleophilic addition or electron transfer mechanism. In this case, the amino group in N-(3-aminopropyl)diethanolamine acts as a nucleophile to attack the epoxy group in 2-[(thiophen-2-ylmethoxy)methyl]oxirane, resulting in the cleavage of the epoxy bond and the formation of a new carbon-nitrogen bond, thereby achieving the ring-opening reaction of the amino group.

[0031] Technical effects and mechanisms:

[0032] 1) Technical effect of fluorothio group: Fluorothio group (F3S) has strong electronegativity and can attract positive charges on adjacent atoms, thereby stabilizing the molecular structure. In the grinding interface enhancer, fluorothio group can increase the electrostatic repulsion between molecules and reduce the attraction between molecules, thereby improving the grinding efficiency. In addition, fluorothio group can also increase the hydrophobicity of molecules and improve the stability of surfactants in organic phases.

[0033] 2) Technical effect of thienyl group: thienyl group is a structural unit containing an aromatic ring, which has high thermal stability and chemical inertness. In the interface enhancer for grinding, thienyl group can provide rigidity and planarity, which helps to form a stable molecular structure. In addition, thienyl group also has certain polarity and electron-withdrawing effect, which can interact with surrounding polar or non-polar molecules, thereby improving grinding efficiency.

[0034] 3) Technical effect of diethanolamine: Diethanolamine is a compound with two alcoholic hydroxyl groups, which has good solubility and dispersibility. In the grinding interface enhancer, diethanolamine can combine with other molecules through hydrogen bonding to form stable aggregates. In addition, diethanolamine can also be adsorbed on the solid surface through electrostatic attraction, reducing the friction between solid particles, thereby improving grinding efficiency.

[0035] In summary, the solid electrolyte material of the present invention has high ionic conductivity and mechanical strength through the synergistic effect of inorganic and organic components, and can effectively prevent lithium dendrites from penetrating the electrolyte, thereby extending the cycle life of the battery. Experimental results show that the lithium metal battery using the solid electrolyte material of the present invention still maintains a good capacity retention rate after 500 cycles, and the safety is significantly improved.

[0036] The solid electrolyte material of the present invention has high ionic conductivity and mechanical strength through the synergistic effect of inorganic and organic components, and can effectively prevent lithium dendrites from penetrating the electrolyte, thereby extending the cycle life of the battery. Experimental results show that the lithium metal battery using the solid electrolyte material of the present invention still maintains a good capacity retention rate after 500 cycles, and the safety is significantly improved. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The experimental methods without specific conditions in the examples are usually carried out according to conventional conditions and conditions described in the manual, or according to conditions recommended by the manufacturer. The general equipment, materials, reagents, etc. used are all available from commercial channels unless otherwise specified.

[0039] Example 1

[0040] An electrolyte for inhibiting dendrite growth of a solid-state lithium metal battery and a preparation process thereof, characterized in that the electrolyte comprises the following steps:

[0041] (1) 50 g of inorganic electrolyte powder and 10 g of organic polymer matrix were mixed evenly, and then 5 g of lithium salt and 1 g of interface enhancer were added, and ball milling was performed for 1 hour;

[0042] (2) hot pressing the mixture in a mold, and annealing the hot pressed electrolyte material to improve the density and ion conductivity of the material, thereby obtaining the electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries.

[0043] The inorganic solid electrolyte material is Li7La3Zr2O 12 (LLZO).

[0044] The organic polymer matrix is ​​polyethylene glycol (PEG).

[0045] The lithium salt is LiTFSI (lithium bis(trifluoromethanesulfonyl)imide).

[0046] The interface enhancer is composed of the following components:

[0047] Fluoro-4-(pentafluorothio)aniline (CAS: 2993-24-0): 20 g;

[0048] 2-[(Thiophen-2-ylmethoxy)methyl]oxirane (CAS: 80910-06-1): 0.04 g;

[0049] 1,4-Dimethyl-2-pyrrolidone (CAS: 2555-04-6): 1000g;

[0050] Ethylenediamine (CAS: 107-15-3): 2g;

[0051] N-(3-Aminopropyl)diethanolamine (CAS: 4985-85-7): 17 g.

[0052] The preparation method of the interface enhancer:

[0053] N-(3-aminopropyl)diethanolamine and 2-[(thiophen-2-ylmethoxy)methyl]ethylene oxide are added to 1,4-dimethyl-2-pyrrolidone, and ethylenediamine is added after stirring and mixing evenly, and then stirred and reacted at 60°C for 50 minutes; then fluoro-4-(pentafluorothio)aniline is added, the temperature is controlled at 60°C, the reaction is stirred for 120 minutes, and 1,4-dimethyl-2-pyrrolidone is distilled off to obtain the interface enhancer.

[0054] The rotation speed of the ball milling process is 300 rpm, and the ball-to-material ratio is 10:1.

[0055] The hot pressing process: the hot pressing temperature is 80° C., the pressure is 50 MPa, and the time is 8 hours.

[0056] The heat treatment process: annealing temperature is 100° C. and time is 6 hours.

[0057] Example 2

[0058] An electrolyte for inhibiting dendrite growth of a solid-state lithium metal battery and a preparation process thereof, characterized in that the electrolyte comprises the following steps:

[0059] (1) 60 g of inorganic electrolyte powder and 30 g of organic polymer matrix were mixed evenly, and then 10 g of lithium salt and 3.5 g of interface enhancer were added, and ball milling was performed for 2 hours;

[0060] (2) hot pressing the mixture in a mold, and annealing the hot pressed electrolyte material to improve the density and ion conductivity of the material, thereby obtaining the electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries.

[0061] The inorganic solid electrolyte material is Li 10 GeP2S 12 (LGPS).

[0062] The organic polymer matrix is ​​polyvinylidene fluoride (PVDF).

[0063] The lithium salt is LiClO4.

[0064] The interface enhancer is composed of the following components:

[0065] Fluoro-4-(pentafluorothio)aniline (CAS: 2993-24-0): 30 g;

[0066] 2-[(Thiophen-2-ylmethoxy)methyl]oxirane (CAS: 80910-06-1): 0.2 g;

[0067] 1,4-Dimethyl-2-pyrrolidone (CAS: 2555-04-6): 1150g;

[0068] Ethylenediamine (CAS: 107-15-3): 3g;

[0069] N-(3-Aminopropyl)diethanolamine (CAS: 4985-85-7): 23 g.

[0070] The preparation method of the interface enhancer:

[0071] N-(3-aminopropyl)diethanolamine and 2-[(thiophen-2-ylmethoxy)methyl]ethylene oxide are added to 1,4-dimethyl-2-pyrrolidone, and ethylenediamine is added after stirring and mixing evenly, and then stirred and reacted at 70°C for 75 minutes; then fluoro-4-(pentafluorothio)aniline is added, the temperature is controlled at 70°C, the reaction is stirred for 110 minutes, and 1,4-dimethyl-2-pyrrolidone is distilled off to obtain the interface enhancer.

[0072] The rotation speed of the ball milling process is 400 rpm, and the ball-to-material ratio is 15:1.

[0073] The hot pressing process: the hot pressing temperature is 100° C., the pressure is 25 MPa, and the time is 6 hours.

[0074] The heat treatment process: annealing temperature is 125° C. and time is 4 hours.

[0075] Example 3

[0076] An electrolyte for inhibiting dendrite growth of a solid-state lithium metal battery and a preparation process thereof, characterized in that the electrolyte comprises the following steps:

[0077] (1) 70 g of inorganic electrolyte powder and 30 g of organic polymer matrix were mixed uniformly, and then 15 g of lithium salt and 7.5 g of interface enhancer were added, and ball milling was performed for 3 hours;

[0078] (2) hot pressing the mixture in a mold, and annealing the hot pressed electrolyte material to improve the density and ion conductivity of the material, thereby obtaining the electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries.

[0079] The inorganic solid electrolyte material is Li 10 GeP2S 12 (LGPS).

[0080] The organic polymer matrix is ​​polyvinylidene fluoride (PVDF).

[0081] The lithium salt is LiClO4.

[0082] The interface enhancer is composed of the following components:

[0083] Fluoro-4-(pentafluorothio)aniline (CAS: 2993-24-0): 30 g;

[0084] 2-[(Thiophen-2-ylmethoxy)methyl]oxirane (CAS: 80910-06-1): 0.35 g;

[0085] 1,4-Dimethyl-2-pyrrolidone (CAS: 2555-04-6): 1300g;

[0086] Ethylenediamine (CAS: 107-15-3): 4g;

[0087] N-(3-aminopropyl)diethanolamine (CAS: 4985-85-7): 30 g.

[0088] The preparation method of the interface enhancer:

[0089] N-(3-aminopropyl)diethanolamine and 2-[(thiophen-2-ylmethoxy)methyl]ethylene oxide are added to 1,4-dimethyl-2-pyrrolidone, and ethylenediamine is added after stirring and mixing evenly, and then stirred and reacted at 70°C for 75 minutes; then fluoro-4-(pentafluorothio)aniline is added, the temperature is controlled at 70°C, the reaction is stirred for 110 minutes, and 1,4-dimethyl-2-pyrrolidone is distilled off to obtain the interface enhancer.

[0090] The rotation speed of the ball milling process is 400 rpm, and the ball-to-material ratio is 15:1.

[0091] The hot pressing process: the hot pressing temperature is 100° C., the pressure is 40 MPa, and the time is 6 hours.

[0092] The heat treatment process: annealing temperature is 125° C. and time is 4 hours.

[0093] Example 4

[0094] An electrolyte for inhibiting dendrite growth of a solid-state lithium metal battery and a preparation process thereof, characterized in that the electrolyte comprises the following steps:

[0095] (1) 80 g of inorganic electrolyte powder and 40 g of organic polymer matrix were mixed uniformly, and then 20 g of lithium salt and 10 g of interface enhancer were added, and ball milling was performed for 4 hours;

[0096] (2) hot pressing the mixture in a mold, and annealing the hot pressed electrolyte material to improve the density and ion conductivity of the material, thereby obtaining the electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries.

[0097] The inorganic solid electrolyte material is Li6PS5Cl.

[0098] The organic polymer matrix is ​​polyurethane (PU).

[0099] The lithium salt is LiBF4.

[0100] The interface enhancer is composed of the following components:

[0101] Fluoro-4-(pentafluorothio)aniline (CAS: 2993-24-0): 40 g;

[0102] 2-[(Thiophen-2-ylmethoxy)methyl]oxirane (CAS: 80910-06-1): 0.5 g;

[0103] 1,4-Dimethyl-2-pyrrolidone (CAS: 2555-04-6): 1400g;

[0104] Ethylenediamine (CAS: 107-15-3): 5g;

[0105] N-(3-Aminopropyl)diethanolamine (CAS: 4985-85-7): 34 g.

[0106] The preparation method of the interface enhancer:

[0107] N-(3-aminopropyl)diethanolamine and 2-[(thiophen-2-ylmethoxy)methyl]ethylene oxide are added to 1,4-dimethyl-2-pyrrolidone, and ethylenediamine is added after stirring and mixing evenly, and then stirred and reacted at 80°C for 100 minutes; then fluoro-4-(pentafluorothio)aniline is added and the temperature is controlled at 80°C, and the reaction is stirred for 100 minutes, and 1,4-dimethyl-2-pyrrolidone is distilled off to obtain the interface enhancer.

[0108] The rotation speed of the ball milling process is 500 rpm, and the ball-to-material ratio is 20:1.

[0109] The hot pressing process: the hot pressing temperature is 120° C., the pressure is 10 MPa, and the time is 4 hours.

[0110] The heat treatment process: the annealing temperature is 150° C. and the time is 2 hours.

[0111] Comparative Example 1

[0112] The preparation of the electrolyte is basically the same as that of Example 1, except that no interface enhancer is added in step (1).

[0113] Comparative Example 2

[0114] The preparation of the electrolyte is basically the same as that of Example 1, except that 2-[(thiophen-2-ylmethoxy)methyl]ethylene oxide is not added during the preparation of the interface enhancer in step (1).

[0115] Comparative Example 3

[0116] The preparation of the electrolyte is basically the same as that of Example 1, except that N-(3-aminopropyl)diethanolamine is not added during the preparation of the interface enhancer in step (1).

[0117] Test method:

[0118] Ionic conductivity test: Electrochemical impedance spectroscopy (EIS) was used to test the ionic conductivity of the electrolyte material at room temperature in the frequency range of 1 Hz to 1 MHz.

[0119] Interface impedance test: The prepared solid electrolyte material and lithium metal electrode were assembled into a symmetrical battery, and the interface impedance was tested using electrochemical impedance spectroscopy at room temperature.

[0120] Battery cycle performance test: A lithium metal battery with the solid electrolyte of the present invention was assembled and tested at 2 mA / cm 2 Cyclic tests were carried out at a current density of 1000 Ω to measure the cycle life and capacity retention rate.

[0121] Test results:

[0122] Table 1

[0123]

[0124] The solid electrolyte material of the embodiment of the present invention exhibits high ionic conductivity, interface stability and capacity retention rate by optimizing the ratio of inorganic and organic components and a suitable preparation process. The test results show that the use of the material of the present invention can significantly inhibit the growth of lithium dendrites and improve the cycle life and safety performance of the battery. In particular, after 500 cycles, the capacity retention rate of the battery can still be maintained at more than 86%, which is significantly better than existing solid electrolyte materials.

[0125] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference may be made to the description in other embodiments.

[0126] The above-mentioned embodiments only express the implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and a preparation process thereof, characterized in that: The following steps are involved: (1) 50-80 parts of inorganic electrolyte powder and 10-40 parts of organic polymer matrix are mixed uniformly by mass, and then 5-20 parts of lithium salt and 1-10 parts of interface enhancer are added, and ball milling is performed for 1-4 hours; (2) hot pressing the mixture in a mold, and annealing the hot pressed electrolyte material to improve the density and ion conductivity of the material, thereby obtaining the electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries.

2. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 1, characterized in that: The inorganic solid electrolyte material is Li7La3Zr2O 12 , Li 10 GeP2S 12 or Li6PS5Cl.

3. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 1, characterized in that: The organic polymer matrix is ​​at least one of polyethylene glycol, polyvinylidene fluoride, polyurethane or polyethylene oxide, and has a molecular weight ranging from 10,000 to 500,000.

4. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 1, characterized in that: The lithium salt is at least one of LiTFSI, LiClO4 or LiBF4.

5. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 1, characterized in that: The interface enhancer is composed of the following components: Fluoro-4-(pentafluorothio)aniline: 20-40 parts; 2-[(Thiophen-2-ylmethoxy)methyl]ethylene oxide: 0.04-0.5 parts; 1,4-dimethyl-2-pyrrolidone: 1000-1400 parts; Ethylenediamine: 2-5 parts; N-(3-aminopropyl)diethanolamine: 17-34 parts.

6. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 5, characterized in that: The preparation method of the interface enhancer: According to the mass fractions, N-(3-aminopropyl)diethanolamine and 2-[(thiophen-2-ylmethoxy)methyl]ethylene oxide are added to 1,4-dimethyl-2-pyrrolidone, and ethylenediamine is added after stirring and mixing evenly, and then stirred and reacted at 60-80° C. for 50-100 minutes; then fluoro-4-(pentafluorothio)aniline is added and the temperature is controlled at 60-80° C., and the reaction is stirred for 100-120 minutes, and 1,4-dimethyl-2-pyrrolidone is distilled off to obtain the interface enhancer.

7. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 1, characterized in that: The rotation speed of the ball milling process is 300-500 rpm, and the ball-to-material ratio is 10:1-20:

1.

8. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 1, characterized in that: The hot pressing process: the hot pressing temperature is 80-120°C, the pressure is 10-50MPa, and the time is 4-8 hours.

9. The electrolyte for inhibiting dendrite growth of solid-state lithium metal batteries and the preparation process thereof according to claim 1, characterized in that: The heat treatment process: the annealing temperature is 100-150° C. and the time is 2-6 hours.

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