A high-entropy argyrodite solid-state electrolyte, a preparation method and application thereof

Abstract

The application discloses a high-entropy argyrodite sulfide solid electrolyte and a preparation method and application thereof, and belongs to the solid-state battery field. A high-entropy argyrodite sulfide solid electrolyte with excellent ion conductivity and stability is obtained by completely replacing P elements with Sb elements in a sulfide solid electrolyte Li6PS5I (lithium phosphorus sulfide iodide), and then doping and modifying Ge, Si and As elements on the basis of Li6SbS5I, and by adjusting the proportion of the above cation elements. The electrolyte has excellent electrochemical performance by designing and assembling a full solid-state battery.

Description

Technical Field

[0001] This application relates to a high-entropy silver-germanium sulfide solid electrolyte, its preparation method and application, belonging to the field of sulfide solid batteries. Background Technology

[0002] In recent years, with the continuous growth of energy demand and the advancement of sustainable development goals, high-energy-density and high-safety battery systems have become a research hotspot. All-solid-state lithium batteries (ASSLBs), due to their use of solid electrolytes instead of traditional liquid electrolytes, offer higher safety, a wider electrochemical window, and potentially high energy density, making them an ideal choice for next-generation energy storage systems. However, the limitations of solid electrolyte performance, especially low ionic conductivity, insufficient electrochemical stability, and poor interfacial compatibility, remain one of the key bottlenecks restricting the practical application of ASSLBs. High-entropy materials are a new type of material that achieves high mixing entropy (ΔS) through multi-component design. Traditional solid electrolytes are usually based on the optimization of a single or a few components, while high-entropy design, by introducing multiple ions to form a solid solution structure, greatly enriches the design freedom of materials, helps increase the structural and thermodynamic stability of materials, and can increase the disorder of materials, thereby reducing the lithium-ion migration barrier, which is conducive to the development of novel sulfide electrolytes with excellent performance. Currently, the room-temperature ionic conductivity of common sulfide solid electrolytes generally does not exceed 10 mS / cm. -1 However, due to its poor interfacial compatibility with lithium-ion battery cathode materials, limited electrochemical stability window, and poor stability to lithium metal on the anode side, the practical application of sulfide-germanium ore-based solid electrolytes is restricted. Therefore, there is an urgent need to find low-cost and higher-performance sulfide solid electrolytes for use in all-solid-state lithium-ion batteries. Summary of the Invention

[0003] According to one aspect of this application, a high-entropy silver-germanium sulfide solid electrolyte is provided. Ge, Si, and As-doped Li6SbS5I (lithium antimony sulfide iodide) silver-germanium sulfide solid electrolyte is prepared by planetary ball milling and solid-state sintering, and then assembled into an all-solid-state battery, thereby improving the ionic conductivity and electrochemical stability of the electrolyte and promoting its commercial development.

[0004] According to one aspect of this application, a high-entropy silver-germanium sulfide solid electrolyte with the chemical formula Li is provided. 6+2x / 3 (GeSiAs) x / 3 Sb 1-x S5I, where 0 <x<1。

[0005] Optionally, x is selected from any value of 1 / 4, 1 / 2, 2 / 3, 4 / 5, 5 / 6, 7 / 8, 9 / 10 or a range of values ​​between any two.

[0006] The ionic conductivity of the silver-germanium sulfide-type solid electrolyte is 10–15.5 mS / cm at 20–30 °C. -1 After hot pressing, it can exceed 40 mS cm -1 This meets the application requirements of all-solid-state lithium-ion batteries.

[0007] Optionally, the high-entropy silver-germanium sulfide solid electrolyte is Li 6.167 (GeSiAs) 0.083 Sb 0.75 S5I, Li 6.333 (GeSiAs) 0.167 Sb 0.5 S5I, Li 6.444 (GeSiAs) 0.222 Sb 0.333 S5I, Li 6.533 (GeSiAs) 0.267 Sb 0.2 S5I, Li 6.556 (GeSiAs) 0.278 Sb 0.167 S5I, Li 6.583 (GeSiAs) 0.292 Sb 0.125 S5I, Li 6.6 (GeSiAs) 0.3 Sb 0.1 At least one of S5I.

[0008] According to another aspect of this application, a method for preparing the above-mentioned high-entropy silver-germanium sulfide solid electrolyte is also provided, comprising the following steps:

[0009] Includes the following steps:

[0010] The raw materials containing SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3 and elemental sulfur powder are ball-milled, roasted, pressed into tablets, and sintered to obtain the high-entropy silver-germanium sulfide solid electrolyte.

[0011] The molar ratio of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3 to elemental sulfur powder is 0.11–0.45: 3.56–4.22: 0.11–0.45: 1.38–1.51: 0.52–0.08: 0.06–0.23: 1.20–0.63.

[0012] The ball mill rotates at a speed of 100–500 rpm. -1 ;

[0013] Optionally, the ball mill rotates at a speed of 300–500 r / min. -1 ;

[0014] Optionally, the ball mill rotates at a speed of 100 rpm. -1 200r min -1 300r min -1 400r min -1 500rmin -1 Any value in the range, or any value between the two.

[0015] The ball milling time is 45 to 1200 minutes.

[0016] Optionally, the ball milling time is 600–1140 min;

[0017] Optionally, the ball milling time is any value among 600 min, 700 min, 800 min, 900 min, 1000 min, 1100 min, and 1140 min, or a range between any two.

[0018] Optionally, a pre-grinding step is also included before ball milling.

[0019] Optionally, the pre-grinding conditions include: a rotational speed of 100–300 rpm. -1 The pre-grinding time is 60-120 minutes.

[0020] Optionally, the pre-grinding speed is selected from 100 r / min. -1 200r min -1 300r min -1 Any value in the range or any value between the two.

[0021] Optionally, the pre-grinding time is selected from any value of 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, or any range between two.

[0022] The roasting temperature is 400–500°C;

[0023] The roasting time is 8 to 12 hours.

[0024] Optionally, the roasting time is selected from any value of 8h, 9h, 10h, 11h, 12h or a range between any two.

[0025] The pressure of the tablet is 10-15 MPa.

[0026] Optionally, the pressure of the tablet is selected from any value of 10MPa, 11MPa, 12MPa, 13MPa, 14MPa, 15MPa or a range between any two.

[0027] After ball milling, an amorphous phase mixture of sulfide solid electrolyte was obtained, which was then cold-pressed to obtain a raw embryo.

[0028] The sintering atmosphere is a non-reactive gas atmosphere;

[0029] The inert gas atmosphere includes a nitrogen atmosphere and an inert gas atmosphere.

[0030] The sintering temperature is 200–475°C;

[0031] Optionally, the sintering temperature is selected from any value among 200℃, 250℃, 300℃, 350℃, 400℃, and 475℃, or any range between the two.

[0032] The heating rate for sintering is 5–10 °C / min;

[0033] Optionally, the sintering heating rate is selected from 5℃ / min. -1 6℃min -1 7℃min -1 8℃min -1 9℃min -1 10℃min -1 Any value in the range or any value between the two.

[0034] The sintering time is 6 to 12 hours.

[0035] Optionally, the sintering time is selected from any value of 6h, 7h, 8h, 9h, 10h, 11h, 12h or any range between the two.

[0036] Optionally, the sintering process further includes a grinding into powder step.

[0037] According to another aspect of this application, at least one of the above-described high-entropy silver-germanium sulfide solid electrolyte and the high-entropy silver-germanium sulfide solid electrolyte prepared according to the above preparation method is provided as an all-solid-state lithium-ion battery electrolyte.

[0038] The negative electrode uses pre-cut Li foil and In foil.

[0039] This application discloses a high-entropy silver-germanium sulfide solid electrolyte, its preparation method, and its application. This application belongs to the field of solid-state batteries. This application mainly involves doping the sulfide solid electrolyte Li6SbS5I (lithium antimony sulfide iodide) with Ge, Si, and As to obtain a high-entropy silver-germanium sulfide solid electrolyte with excellent ionic conductivity. Through the design and assembly of an all-solid-state lithium-ion battery, it is demonstrated that this electrolyte exhibits excellent electrochemical stability.

[0040] The beneficial effects that this application can produce include:

[0041] The high-entropy sulfide solid electrolyte provided in this application has a sulfide-germanium ore structure that effectively shortens the Li... + The transport path is improved, reducing grain boundary confinement and ensuring that the sulfide solid electrolyte has suitable ionic conductivity; doping with Ge, Si, and As elements can reduce Li... + The migration barrier significantly improves the ionic conductivity of the electrolyte; LiI can form a protective layer during charging and discharging, effectively suppressing dendrite growth and improving the interfacial stability between the electrolyte and the positive and negative electrode materials, which helps to realize fast-charging all-solid-state lithium-ion batteries; Ge, Si, and As doping replaces the P(Sb) sites in the sulfide-germanium ore type electrolyte, which is expected to improve the air stability of the electrolyte and realize high-voltage all-solid-state lithium-ion batteries, further improving the energy density and cycle life of the battery. Attached Figure Description

[0042] Figure 1 This is an X-ray diffraction pattern of a high-entropy silver-germanium sulfide solid electrolyte according to an embodiment of this application.

[0043] Figure 2 This is the Raman spectrum of a high-entropy silver-germanium sulfide solid electrolyte according to an embodiment of this application.

[0044] Figure 3 This is the electrochemical impedance spectroscopy of a high-entropy silver-germanium sulfide solid electrolyte according to an embodiment of this application.

[0045] Figure 4 Li in Embodiment 5 of this application 6.556 (GeSiAs) 0.278 Sb 0.167 Scanning electron microscope image and energy dispersive spectroscopy (EDS) spectrum of S5I electrolyte.

[0046] Figure 5 Li in Embodiment 5 of this application 6.556 (GeSiAs) 0.278 Sb 0.167 Electrochemical impedance spectroscopy of S5I electrolyte measured at room temperature after hot pressing.

[0047] Figure 6 Li is used in Embodiment 5 of this application. 6.556 (GeSiAs) 0.278 Sb 0.167 The charge-discharge cycle performance of an all-solid-state lithium-ion battery assembled with S5I as the electrolyte is shown in the figure. Detailed Implementation

[0048] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0049] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.

[0050] According to one embodiment of this application:

[0051] A mixture of SiS2 (0.11–0.45 molar ratio), Li2S (3.56–4.22 molar ratio), GeS2 (0.11–0.45 molar ratio), LiI (1.38–1.51 molar ratio), Sb2S3 (0.52–0.08 molar ratio), As2S3 (0.06–0.23 molar ratio), and elemental sulfur powder (5% excess) (1.20–0.63 molar ratio) was placed in a ball mill jar and pre-milled at 100–300 rpm for 1–2 h, followed by ball milling at 300–500 rpm for 10–20 h to obtain an amorphous phase mixture of high-entropy sulfide solid electrolyte. This mixture was then cold-pressed to obtain a preform, placed in a quartz tube, and heated at room temperature to 400–500 °C for 8–12 h. After cooling to room temperature, a ceramic-phase high-entropy silver-germanium sulfide solid electrolyte was obtained and removed from the ball mill jar for later use.

[0052] The ball-milled amorphous mixture was compressed into tablets at a pressure of 10-15 MPa and a tablet diameter of 10-13 cm, and then heated at 5-10 °C for 1 minute under Ar protection. -1 The heating rate is increased to 200-475℃, held for 6-12 hours, and then naturally cooled to room temperature. After that, the sintered electrolyte is ground into powder for later use.

[0053] A high-entropy silver-germanium sulfide solid electrolyte was placed in a solid-state battery mold, and the interface was kept in close contact by applying a pressure of 200–500 MPa. Cut Li and In foils were placed on the negative electrode side, and NCM811 (LiNi) was used as the positive electrode. 0.8 Co 0.1 Mn 0.1 O2), NCM622(LiNi) 0.6 Co 0.2 Mn 0.2 One of O2 and LCO (LiCoO2), with a loading of 7-12 mg / cm³. -2The sample was placed in a solid-state battery test mold, and the interface was kept in close contact by applying a pressure of 200–500 MPa. Finally, its electrochemical performance was tested.

[0054] Example 1

[0055] A mixture of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3, and elemental sulfur powder in a molar ratio of 0.11:3.56:0.11:1.38:0.52:0.06:1.20 was placed in a ball mill jar and pre-milled at 100 rpm for 1 h, then ball-milled at 300 rpm for 2 h, and finally ball-milled at 500 rpm for 20 h to obtain an amorphous mixture of high-entropy silver-germanium sulfide solid electrolyte. This mixture was then cold-pressed to obtain a green blank, which was placed in a quartz tube and heated to 450℃ at room temperature for 12 h. The temperature was then lowered to room temperature to obtain a ceramic-phase sulfide solid electrolyte, Li. 6.167 (GeSiAs) 0.083 Sb 0.75 S5I. The obtained electrolyte was poured into a solid-state battery mold and pressed into a sheet under a pressure of 350 MPa. The impedance of the electrolyte was measured to be approximately 520 Ω. The obtained X-ray diffraction pattern is attached. Figure 1 As shown in the attached image, the measured Raman spectrum is as follows. Figure 2 As shown.

[0056] Example 2

[0057] A mixture of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3, and elemental sulfur powder in a molar ratio of 0.24:3.80:0.24:1.42:0.36:0.12:1.00 was placed in a ball mill jar and pre-milled at 100 rpm for 1 h, then ball-milled at 300 rpm for 2 h, and finally ball-milled at 500 rpm for 20 h to obtain an amorphous mixture of high-entropy silver-germanium sulfide solid electrolyte. This mixture was then cold-pressed to obtain a green blank, which was placed in a quartz tube and heated to 450°C at room temperature for 12 h. The temperature was then lowered to room temperature to obtain a ceramic-phase sulfide solid electrolyte, Li. 6.333 (GeSiAs) 0.167 Sb 0.5 S5I. The obtained electrolyte was poured into a solid-state battery mold and pressed into a sheet under a pressure of 350 MPa. The impedance of the electrolyte was measured to be 27.46 Ω (see attached). Figure 3 (As shown). The measured X-ray diffraction pattern is attached. Figure 1 As shown in the attached image, the measured Raman spectrum is as follows. Figure 2 As shown.

[0058] Example 3

[0059] A mixture of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3, and elemental sulfur powder in a molar ratio of 0.32:3.97:0.32:1.46:0.24:0.16:0.85 was placed in a ball mill jar and pre-milled at 100 rpm for 1 h, then ball-milled at 300 rpm for 2 h, and finally ball-milled at 500 rpm for 20 h to obtain an amorphous mixture of high-entropy silver-germanium sulfide solid electrolyte. This mixture was then cold-pressed to obtain a green blank, which was placed in a quartz tube and heated to 450°C at room temperature for 12 h. The temperature was then lowered to room temperature to obtain a ceramic-phase sulfide solid electrolyte, Li. 6.444 (GeSiAs) 0.222 Sb 0.333 S5I. The obtained electrolyte was poured into a solid-state battery mold and pressed into a sheet under a pressure of 350 MPa. The impedance of the electrolyte was measured to be 12.78 Ω (see attached). Figure 3 (As shown). The measured X-ray diffraction pattern is attached. Figure 1 As shown in the attached image, the measured Raman spectrum is as follows. Figure 2 As shown.

[0060] Example 4

[0061] A mixture of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3, and elemental sulfur powder in a molar ratio of 0.40:4.11:0.40:1.49:0.15:0.20:0.73 was placed in a ball mill jar and pre-milled at 100 rpm for 1 h, then ball-milled at 300 rpm for 2 h, and finally ball-milled at 500 rpm for 20 h to obtain an amorphous mixture of high-entropy silver-germanium sulfide solid electrolyte. This mixture was then cold-pressed to obtain a green blank, which was placed in a quartz tube and heated to 450°C at room temperature for 12 h. The temperature was then lowered to room temperature to obtain a ceramic-phase sulfide solid electrolyte, Li. 6.533 (GeSiAs) 0.267 Sb 0.2 S5I. The obtained electrolyte was poured into a solid-state battery mold and pressed into a sheet under a pressure of 350 MPa. The impedance of the electrolyte was measured to be 7.43 Ω (see attached). Figure 3 (As shown). The measured X-ray diffraction pattern is attached. Figure 1 As shown in the attached image, the measured Raman spectrum is as follows. Figure 2 As shown.

[0062] Example 5

[0063] A mixture of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3, and elemental sulfur powder in a molar ratio of 0.41:4.15:0.41:1.49:0.12:0.21:0.70 was placed in a ball mill jar and pre-milled at 100 rpm for 1 h, then ball-milled at 300 rpm for 2 h, and finally ball-milled at 500 rpm for 20 h to obtain an amorphous mixture of high-entropy silver-germanium sulfide solid electrolyte. This mixture was then cold-pressed to obtain a green blank, which was placed in a quartz tube and heated to 450°C at room temperature for 12 h. The temperature was then lowered to room temperature to obtain a ceramic-phase sulfide solid electrolyte, Li. 6.556 (GeSiAs) 0.278 Sb 0.167 The elemental distribution of S5I, as shown in its scanning electron microscope image and energy-dispersive spectroscopy, is attached. Figure 4 As shown. The obtained electrolyte was poured into a solid-state battery mold and pressed into a sheet under a pressure of 350 MPa. The impedance of the electrolyte was measured to be 6.20 Ω (as shown in the attached figure). Figure 3 (As shown). The impedance of the electrolyte was measured at room temperature after hot pressing, and the calculated ionic conductivity of the electrolyte after hot pressing exceeded 40 mS / cm. -1 (as attached) Figure 5 (As shown). The measured X-ray diffraction pattern is attached. Figure 1 As shown in the attached image, the measured Raman spectrum is as follows. Figure 2 As shown. Using Li-In as the negative electrode and NCM811 as the positive electrode, with a current of 4.4 mA / cm²... -2 The current density is 1.8 mg / cm³. -2 The positive electrode loading was measured, and a long-cycle test was conducted at 30°C. The test results showed that the battery performed well at 15C (1C = 160 mA g). -1 Cycling at a higher rate for over 1700 cycles, with a capacity retention rate exceeding 80% (see attached). Figure 6 (As shown).

[0064] Example 6

[0065] A mixture of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3, and elemental sulfur powder in a molar ratio of 0.44:4.19:0.44:1.50:0.09:0.22:0.66 was placed in a ball mill jar and pre-milled at 100 rpm for 1 h, then ball-milled at 300 rpm for 2 h, and finally ball-milled at 500 rpm for 20 h to obtain an amorphous mixture of high-entropy silver-germanium sulfide solid electrolyte. This mixture was then cold-pressed to obtain a green blank, which was placed in a quartz tube and heated to 450℃ at room temperature for 12 h. The temperature was then lowered to room temperature to obtain a ceramic-phase sulfide solid electrolyte, Li. 6.583 (GeSiAs) 0.292 Sb 0.125S5I. The obtained electrolyte was poured into a solid-state battery mold and pressed into a sheet under a pressure of 350 MPa. The impedance of the electrolyte was measured to be 7.24 Ω (see attached). Figure 3 (As shown). The measured X-ray diffraction pattern is attached. Figure 1 As shown in the attached image, the measured Raman spectrum is as follows. Figure 2 As shown.

[0066] Example 7

[0067] A mixture of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3, and elemental sulfur powder in a molar ratio of 0.45:4.22:0.45:1.51:0.08:0.23:0.63 was placed in a ball mill jar and pre-milled at 100 rpm for 1 h, then ball-milled at 300 rpm for 2 h, and finally ball-milled at 500 rpm for 20 h to obtain an amorphous mixture of high-entropy silver-germanium sulfide solid electrolyte. This mixture was then cold-pressed to obtain a green blank, which was placed in a quartz tube and heated to 450°C at room temperature for 12 h. The temperature was then lowered to room temperature to obtain a ceramic-phase sulfide solid electrolyte, Li. 6.6 (GeSiAs) 0.3 Sb 0.1 S5I. The obtained electrolyte was poured into a solid-state battery mold and pressed into a sheet under a pressure of 350 MPa. The impedance of the electrolyte was measured to be 6.82 Ω (see attached). Figure 3 (As shown). The measured X-ray diffraction pattern is attached. Figure 1 As shown in the attached image, the measured Raman spectrum is as follows. Figure 2 As shown.

[0068] Test Example 1

[0069] The X-ray diffraction patterns of the high-entropy silver-germanium sulfide solid electrolytes of Examples 1-7 are shown below. Figure 1 As shown, Ge, Si, and As elements can be well incorporated into the Li6SbS5I lattice. With the increase of x, the diffraction peak corresponding to 49.8° gradually shifts, and the peak intensity ratio gradually changes, indicating that the doping of high-entropy elements causes a change in the lattice constant, but the overall phase composition does not change significantly, indicating that the synthesized high-entropy silver-germanium sulfide solid electrolyte has high purity.

[0070] The Raman spectra of the high-entropy silver-germanium sulfide solid electrolytes in Examples 1-7 are as follows: Figure 2 As shown, 375cm is clearly visible. -1 The corresponding SbS4 3-The characteristic peak indicates the successful preparation of the electrolyte. As x increases, the peak gradually shifts, and the peak intensity ratio gradually changes, indicating that the doping of high-entropy elements causes a change in the lattice constant. However, the overall phase composition and elemental coordination environment do not change significantly, indicating that the synthesized high-entropy silver-germanium sulfide solid electrolyte has high purity.

[0071] The electrochemical impedance spectroscopy spectra of the high-entropy silver-germanium sulfide solid electrolytes in Examples 2-7 are as follows: Figure 3 As shown, it can be clearly seen that with the increase of x, the impedance of the synthesized high-entropy silver-germanium sulfide solid electrolyte first gradually decreases, and when x = 5 / 6 (i.e., Li...), the impedance decreases further. 6.556 (GeSiAs) 0.278 Sb 0.167 The impedance reaches a minimum of 6.20Ω at S5I. Afterward, the impedance gradually increases with increasing x, indicating that only an appropriate doping amount can yield a high-entropy silver-germanium sulfide solid electrolyte with the highest ionic conductivity.

[0072] In Example 5, Li 6.556 (GeSiAs) 0.278 Sb 0.167 Scanning electron microscope (SEM) image and energy dispersive spectroscopy (EDS) spectrum of S5I electrolyte are as follows: Figure 4 As shown in the figure, the electrolyte is spherical in shape composed of thin sheets, and the uniform elemental distribution further proves the successful synthesis of the electrolyte.

[0073] In Example 5, Li 6.556 (GeSiAs) 0.278 Sb 0.167 The electrochemical impedance spectroscopy of S5I electrolyte measured at room temperature after hot pressing is shown below. Figure 5 As shown in the figure, the impedance of the electrolyte after hot pressing at room temperature is 3.135Ω, and the calculated ionic conductivity of the electrolyte after hot pressing exceeds 40 mS / cm. -1 This is the highest value reported in the current literature.

[0074] Using Li in Example 5 6.556 (GeSiAs) 0.278 Sb 0.167 The charge-discharge cycle performance of the all-solid-state lithium-ion battery assembled with S5I as the electrolyte is shown in the figure below. Figure 6 As shown. Using Li-In as the negative electrode and NCM811 as the positive electrode, with a current of 4.4 mA cm⁻¹ -2 The current density is 1.8 mg / cm³. -2 The positive electrode loading was measured, and a long-cycle test was conducted at 30°C. The test results showed that the battery performed well at 15C (1C = 160 mA g). -1After cycling for more than 1700 cycles at a high rate, the capacity retention rate exceeded 80%, further demonstrating that this high-entropy silver-germanium sulfide solid electrolyte has good electrochemical stability.

[0075] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A high-entropy sulfide solid electrolyte of the sulfide type, characterized in that, The chemical formula is Li 6+2x / 3 (GeSiAs) x / 3 Sb 1-x S5I, where 0 <x<1。 2. The sulfide-germanium ore type solid electrolyte according to claim 1, characterized in that, The ionic conductivity of the silver-germanium sulfide-type solid electrolyte is 10–15.5 mS / cm at 20–30 °C. -1 After hot pressing, it can exceed 40 mS cm -1 .

3. A method for preparing a high-entropy silver-germanium sulfide solid electrolyte according to any one of claims 1 or 2, characterized in that, Includes the following steps: The raw materials containing SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3 and elemental sulfur powder are ball-milled, roasted, pressed into tablets, and sintered to obtain the high-entropy silver-germanium sulfide solid electrolyte.

4. The preparation method according to claim 3, characterized in that, The molar ratio of SiS2, Li2S, GeS2, LiI, Sb2S3, As2S3 to elemental sulfur powder is 0.11–0.45: 3.56–4.22: 0.11–0.45: 1.38–1.51: 0.52–0.08: 0.06–0.23: 1.20–0.

63.

5. The preparation method according to claim 3, characterized in that, The ball mill rotates at a speed of 100–500 rpm. -1 ; The ball milling time is 45 to 1200 minutes.

6. The preparation method according to claim 3, characterized in that, The roasting temperature is 400–500°C; The roasting time is 8 to 12 hours.

7. The preparation method according to claim 3, characterized in that, The pressure of the tablet is 10-15 MPa.

8. The preparation method according to claim 3, characterized in that, The sintering atmosphere is a non-reactive gas atmosphere; The inert gas atmosphere includes a nitrogen atmosphere and an inert gas atmosphere.

9. The preparation method according to claim 3, characterized in that, The sintering temperature is 200–475°C; The heating rate for sintering is 5–10 °C / min; The sintering time is 6 to 12 hours.

10. The application of the high-entropy silver-germanium sulfide solid electrolyte as described in claim 1 or 2 as an electrolyte for all-solid-state lithium-ion batteries.

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