Preparation method and application of solid state sodium argyrodite electrolyte material
By introducing halogen elements into sulfide solid electrolytes, the sodium-sulfur silver-germanium ore electrolyte materials are prepared, and the electrochemical stability and hygroscopicity of sulfide electrolyte materials are solved, and a high-performance solid sodium battery electrolyte is realized, with a wider Electrochemical stability window and better mechanical properties.
Patent Information
- Application Number
- CN202411178058.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-27
- Publication Date
- 2024-12-06
AI Technical Summary
The existing sulfide solid electrolyte materials have problems such as poor electrochemical stability, narrow voltage window and poor hygroscopy, which leads to their unstable under high temperature and humidity environments, affecting battery safety.
Halogen elements are introduced into sulfide solid electrolytes to prepare sodium sulfide silver germanium ore electrolyte materials. Through room temperature mechanical ball milling and low-temperature calcination heat treatment methods, their moisture resistance, mechanical ductility and electrochemical stability windows are improved, and their phase with the electrode material is improved. Capacity.
The high room temperature ionic conductivity, wide electrochemical stability window and good mechanical properties of sodium-sulfur silver germanium ore electrolyte materials have been realized, which reduces the compatibility problem with the electrode materials, and the preparation process is simple and safe, with industrial application potential. .
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Figure CN119092803A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of solid-state sodium batteries, and in particular to a preparation method and application of a solid-state sodium argyrodite electrolyte material. Background Art
[0002] Lithium-ion batteries have the advantages of high energy density, no memory effect, and good cycle performance. They are widely used in portable electronic devices and have great potential for use in grid-scale energy storage systems. However, lithium salt reserves are low and costs increase with demand. Compared with lithium, sodium resources are widely distributed, low-cost, and have similar chemical properties to lithium. Therefore, sodium-ion batteries are considered to be the best competitive candidate for lithium-ion batteries.
[0003] However, traditional sodium batteries based on liquid electrolytes have a lot of safety issues, especially when the number of battery packs is increased to achieve large-capacity batteries in electric vehicles and power grid applications, the risks are further magnified. Solid electrolytes have the advantages of high thermal stability, no leakage risk, and can work in a wide temperature range. The development of all-solid-state sodium batteries is an effective way to solve the existing battery safety problems.
[0004] Among solid electrolytes, sulfides have become a research object of great concern in the current solid electrolyte field due to their relatively high ionic conductivity, excellent mechanical properties, low grain boundary resistance and many other advantages. However, there are still some defects that limit their application. On the one hand, the electrochemical stability window is relatively narrow and the interface is incompatible. On the other hand, due to the hygroscopic nature of sulfide electrolytes and poor air stability, even a small amount of moisture in the environment will cause the degradation of sulfide electrolytes and release toxic gas H2S. Summary of the invention
[0005] In view of the difficulties of poor electrochemical stability and narrow voltage window of existing sulfide solid electrolyte materials, the present invention provides a solid sodium argentite electrolyte material, and introduces halogens into the sulfide solid electrolyte. As a quaternary electrolyte of sulfide electrolyte, sodium argentite solid electrolyte contains excess halogen elements, so that the electrolyte exhibits high moisture resistance, high room temperature ionic conductivity and high mechanical ductility, and also has a wider electrochemical stability window (ESW) and better compatibility with electrode materials. In addition, sodium argentite solid electrolyte does not involve rare, expensive or difficult to obtain elements, and better stability can be achieved through reasonable material design. At the same time, the preparation of sodium argentite solid electrolyte is a method of room temperature mechanical ball milling and low temperature calcination heat treatment annealing, which is simple to operate and safer and more environmentally friendly. It is a solid electrolyte with great potential for industrial application.
[0006] In order to achieve the above object, the technical solution adopted by the present invention is:
[0007] The first aspect of the present invention provides a solid sodium argyrodite electrolyte material, the chemical formula of which is Na α M β S5X x , wherein M is one or more of Sb, Si, Sn, and Ge, X is one or more of F, Cl, Br, and I, and 6≤α≤8, 0<β≤1, and 0<x≤1.
[0008] Preferably, in the chemical formula, β=1, x=1.
[0009] Preferably, in the chemical formula, X is one or more of Cl, Br, and I.
[0010] The second aspect of the present invention provides a method for preparing the solid-state argyrodite electrolyte material, comprising the following steps:
[0011] (1) According to the chemical formula of the compound, synthesize Na α M β S5X x The required Na source compound, sulfide and halide are weighed and mixed, and then ball-milled and tableted to obtain compact tablets;
[0012] (2) The compacted sheet is heat treated, cooled and then crushed to obtain the solid-state argyrodite electrolyte material.
[0013] Preferably, in step (1), the Na source compound includes Na2S, the sulfide includes at least one of SiS2, Sb2S3, SnS2, GeS2, and elemental sulfur, and the halide includes at least one of NaCl, NaBr, and NaI.
[0014] Preferably, in step (1), the mass ratio of the balls in the ball milling process is 1:(15-25).
[0015] Preferably, in step (1), the ball milling process comprises the following steps: low-speed ball milling at a speed of 100-140 rpm for 50-70 min; then high-speed ball milling at a speed of 500-600 rpm for 120-160 min; repeating low-speed ball milling and high-speed ball milling for 6-15 times; and maintaining an inert gas atmosphere during the ball milling process.
[0016] Further preferably, during the ball milling process, a forward and reverse rotation mode is adopted when high-speed ball milling is performed. After a certain period of forward rotation, the rotation stops for cooling, and then the rotation is reversed, and then the rotation stops for cooling, and this process is repeated.
[0017] Preferably, in step (1), the tabletting pressure is 150 Mpa-250 Mpa.
[0018] Preferably, in step (2), the heat treatment conditions are: heating to 150-250°C at 5-10°C / min and keeping the temperature for 180-300min.
[0019] The third aspect of the present invention provides a solid-state sodium battery, the structure of the battery comprising the solid-state argyrodite electrolyte material or the solid-state argyrodite electrolyte material prepared by the preparation method, as well as a positive electrode and a negative electrode.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] 1) The sodium argyrodite prepared by the present invention is a quaternary sulfide solid electrolyte among sulfides, which has higher moisture resistance, high room temperature ionic conductivity and high mechanical ductility, as well as a wider electrochemical stability window (ESW) and better compatibility with electrode materials.
[0022] 2) The preparation method of the argyrodite solid electrolyte described in the present invention utilizes room temperature mechanical ball milling and low temperature calcination heat treatment annealing, which is easy to operate and is safer and more environmentally friendly.
[0023] 3) The synthesis steps of the sodium argyrodite solid electrolyte provided by the present invention are simple and detailed, and the material preparation process can be fully automated. At the same time, the sodium argyrodite solid electrolyte does not involve rare, expensive or difficult-to-obtain elements, and can achieve good stability through reasonable material design, and is a solid electrolyte with great potential for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is the XRD pattern of the Na6SbS5Cl solid electrolyte in Example 1;
[0025] Figure 2 is the AC impedance spectrum of the Na6SbS5Cl solid electrolyte in Example 1;
[0026] Figure 3 Graph showing the cycle performance of the Na6SbS5Cl solid electrolyte in Example 1;
[0027] Figure 4 This is the SEM spectrum of the Na6SbS5Cl solid electrolyte in Example 1;
[0028] Figure 5 This is the SEM spectrum of the Na7SiS5Br solid electrolyte in Example 2;
[0029] Figure 6 is Na6SbS5Cl in Example 3 0.5 Br 0.5 Symmetrical performance profile of solid-state electrolytes. DETAILED DESCRIPTION
[0030] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0031] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.
[0032] Example 1
[0033] This embodiment provides a method for preparing a Na6SbS5Cl solid electrolyte, comprising the following steps:
[0034] Weigh 1.3g Na2S, 1.13g Sb2S3, 0.39g NaCl and 0.213g S raw materials in a stoichiometric ratio, pour them into a mortar and grind them to mix evenly, then pour the mixed raw materials into a 100mL ball mill. A total of 60g of ZrO2 balls with diameters of 4mm (20g), 6mm (20g), 8mm (10g), and 10mm (10g) are placed in the jar, and the material ball mass ratio is 1:20. In order to ensure that there is no contact with air, the entire weighing, grinding and ball mill charging process are completed in a glove box. Ball milling is carried out on a planetary ball mill, and an inert atmosphere is maintained throughout the ball milling process. The first step is to pre-grind the raw materials with a low-speed ball mill (120rpm), and the ball milling time is 60min to mix the materials evenly. The second step is to remove the ball mill, send it into a glove box, and scrape off the materials on the inner wall of the ball mill. In the third step, high-speed ball milling (550rpm) is performed forward for 15 minutes, stopped to cool for 5 minutes, and then reversed for 15 minutes, stopped to cool for 5 minutes, and repeated four times. In the fourth step, the ball milling jar after four times of ball milling is sent to the glove box to scrape off the material on the inner wall. In the fifth step, the third and fourth steps are repeated 8 times, and the ball milling is completed. In the glove box, the electrolyte powder after ball milling is poured into a mold and pressed into a disc with a diameter of 16mm and a thickness of 1.2mm at a pressure of 250Mpa. Then the electrolyte disc is placed in a tubular furnace, heated to 150℃ at a heating rate of 5℃ / min in an argon atmosphere, kept warm for 300 minutes, and then cooled naturally. The cooled material is placed in the ball milling jar again and pulverized by low-speed ball milling (120rpm). After sieving with a 300-mesh sieve, it is put into a bottle for standby use.
[0035] Figure 1The XRD spectrum of the sodium argyrotechnite solid electrolyte prepared in Example 1 shows the characteristic peaks of the sodium argyrotechnite solid electrolyte, indicating that the crystal structure of the prepared sodium argyrotechnite solid electrolyte is a cubic structure.
[0036] Figure 2 : is the electrochemical impedance spectroscopy diagram of Example 1. The ionic conductivity of the above-mentioned argyrodite solid electrolyte prepared in Example 1 was tested, and the specific test steps are as follows:
[0037] Weigh 200 mg of Na6SbS5Cl solid electrolyte and pour it into a custom PEEK mold with an inner diameter of 16 mm. Then put it under a hydraulic press and press it into a sheet at a pressure of 250 MPa. The pressure is maintained for electrochemical impedance spectroscopy testing. The ionic conductivity is calculated according to the following formula:
[0038]
[0039] σ is the ionic conductivity, in S cm -2 ; l is the thickness of the solid electrolyte after pressing, in cm; R is the body impedance of the object being measured, in ohm; S is the effective area of the electrode, in cm 2 .
[0040] The calculated ionic conductivity of the solid electrolyte is 2.0×10 -4 S cm -2 .
[0041] Figure 3 is the cycle performance spectrum of Na6SbS5Cl solid electrolyte, Figure 3 It can be seen that the full battery composed of positive electrode material TiS2 and negative electrode material Na3Sn has a high current density of 100mAg -1 The initial discharge capacity at a current density of 105.7 mAh g -1 After 65 cycles, the discharge capacity is 92.8 mAh g -1 , the capacity retention rate was 87.8%, showing excellent stable cycling.
[0042] Figure 4 This is the SEM spectrum of Na6SbS5Cl solid electrolyte. Figure 4 It can be observed that the material is in granular shape with a particle size of 1.5 μm and good density.
[0043] Example 2
[0044] This embodiment provides a method for preparing a Na7SiS5Br solid electrolyte, comprising the following steps:
[0045] Weigh 1.67g Na2S, 0.657g SiS2 and 0.735g NaBr raw materials in a stoichiometric ratio, pour them into a mortar and grind them to mix evenly, then pour the mixed raw materials into a 100mL ball mill. A total of 60g of ZrO2 balls with diameters of 4mm (20g), 6mm (20g), 8mm (10g), and 10mm (10g) are placed in the jar, and the material ball mass ratio is 1:20. In order to ensure that there is no contact with air, the entire weighing, grinding and ball mill charging process are completed in a glove box. Ball milling is carried out on a planetary ball mill, and an inert atmosphere is maintained throughout the ball milling process. The first step is to pre-grind the raw materials with a low-speed ball mill (120rpm) for 60min to mix the materials evenly. The second step is to remove the ball mill, send it into a glove box, and scrape the materials on the inner wall of the ball mill. In the third step, high-speed ball milling (550rpm) is performed forward for 15 minutes, stopped to cool for 5 minutes, and then reversed for 15 minutes, stopped to cool for 5 minutes, and repeated four times. In the fourth step, the ball milling jar after four times of ball milling is sent to the glove box to scrape off the material on the inner wall. In the fifth step, the third and fourth steps are repeated 8 times, and the ball milling is completed. In the glove box, the electrolyte powder after ball milling is poured into a mold and pressed into a disc with a diameter of 16mm and a thickness of 1.2mm at a pressure of 250Mpa. Then the electrolyte disc is placed in a tubular furnace, heated to 150℃ at a heating rate of 5℃ / min in an argon atmosphere, kept warm for 300 minutes, and then cooled naturally. The cooled material is placed in the ball milling jar again and pulverized by low-speed ball milling (120rpm). After sieving with a 300-mesh sieve, it is put into a bottle for standby use.
[0046] Figure 5 This is the SEM spectrum of Na7SiS5Br solid electrolyte. Figure 5 It can be observed that the material is in block shape.
[0047] Example 3
[0048] This embodiment provides a Na6SbS5Cl 0.5 Br 0.5 The method for preparing a solid electrolyte comprises the following steps:
[0049] Weigh 1.22gNa2S, 1.067g Sb2S3, 0.184g NaCl, 0.323g NaBr and 0.201gS raw materials in a stoichiometric ratio, pour them into a mortar and grind them to mix evenly, then pour the mixed raw materials into a 100mL ball mill. And put a total of 60g of ZrO2 balls with diameters of 4mm (20g), 6mm (20g), 8mm (10g), and 10mm (10g) into the jar, and the material ball mass ratio is 1:20. In order to ensure that there is no contact with air, the entire weighing, grinding and ball mill charging process are completed in a glove box. Ball milling is carried out on a planetary ball mill, and an inert atmosphere is maintained throughout the ball milling process. The first step is to pre-grind the raw materials with a low-speed ball mill (120rpm), and the ball milling time is 60min to mix the materials evenly. The second step is to remove the ball mill, send it into a glove box, and scrape off the materials on the inner wall of the ball mill. In the third step, high-speed ball milling (550rpm) is performed forward for 15 minutes, stopped to cool for 5 minutes, and then reversed for 15 minutes, stopped to cool for 5 minutes, and repeated four times. In the fourth step, the ball milling jar after four times of ball milling is sent to the glove box to scrape off the material on the inner wall. In the fifth step, the third and fourth steps are repeated 8 times, and the ball milling is completed. In the glove box, the electrolyte powder after ball milling is poured into a mold and pressed into a disc with a diameter of 16mm and a thickness of 1.2mm at a pressure of 250Mpa. Then the electrolyte disc is placed in a tubular furnace, heated to 150℃ at a heating rate of 5℃ / min in an argon atmosphere, kept warm for 300 minutes, and then cooled naturally. The cooled material is placed in the ball milling jar again and pulverized by low-speed ball milling (120rpm). After sieving with a 300-mesh sieve, it is put into a bottle for standby use.
[0050] Figure 6 Na6SbS5Cl 0.5 Br 0.5 Symmetric performance spectrum of solid electrolytes, by Figure 6 It can be seen that the symmetrical battery assembled by using Na3Sn as both positive and negative electrode materials has a high current density of 100mAg -1 It can cycle stably for more than 200 hours at a current density of , and the polarization voltage can be maintained within 200mV.
[0051] Example 4
[0052] This embodiment provides a Na 6.5 Sb 0.5 Ge 0.5 The preparation method of S5I solid electrolyte comprises the following steps:
[0053] Weigh 1.17g Na2S, 0.464g Sb2S3, 0.373g GeS2, 0.819g NaI and 0.175gS raw materials in a stoichiometric ratio, pour them into a mortar and grind them to mix evenly, then pour the mixed raw materials into a 100mL ball mill. And put a total of 60g of ZrO2 balls with diameters of 4mm (20g), 6mm (20g), 8mm (10g), and 10mm (10g) into the jar, and the material ball mass ratio is 1:20. In order to ensure that there is no contact with air, the entire weighing, grinding and ball mill charging process are completed in a glove box. Ball milling is carried out on a planetary ball mill, and an inert atmosphere is maintained throughout the ball milling process. The first step is to pre-grind the raw materials with a low-speed ball mill (120rpm), and the ball milling time is 60min to mix the materials evenly. The second step is to remove the ball mill, send it into a glove box, and scrape off the materials on the inner wall of the ball mill. In the third step, high-speed ball milling (550rpm) is performed forward for 15 minutes, stopped to cool for 5 minutes, and then reversed for 15 minutes, stopped to cool for 5 minutes, and repeated four times. In the fourth step, the ball milling jar after four times of ball milling is sent to the glove box to scrape off the material on the inner wall. In the fifth step, the third and fourth steps are repeated 8 times, and the ball milling is completed. In the glove box, the electrolyte powder after ball milling is poured into a mold and pressed into a disc with a diameter of 16mm and a thickness of 1.2mm at a pressure of 250Mpa. Then the electrolyte disc is placed in a tubular furnace, heated to 150℃ at a heating rate of 5℃ / min in an argon atmosphere, kept warm for 300 minutes, and then cooled naturally. The cooled material is placed in the ball milling jar again and pulverized by low-speed ball milling (120rpm). After sieving with a 300-mesh sieve, it is put into a bottle for standby use.
[0054] Example 5
[0055] This embodiment provides a Na 6.6 Si 0.4 Sn 0.6 The preparation method of S5Br solid electrolyte comprises the following steps:
[0056] Weigh 1.38g Na2S, 0.233g SiS2, 0.693g SnS2, 0.652g NaBr and 0.041gS raw materials in a stoichiometric ratio, pour them into a mortar and grind them to mix evenly, then pour the mixed raw materials into a 100mL ball mill. And put a total of 60g of ZrO2 balls with diameters of 4mm (20g), 6mm (20g), 8mm (10g), and 10mm (10g) into the jar, and the material ball mass ratio is 1:20. In order to ensure that there is no contact with air, the entire weighing, grinding and ball mill charging process are completed in a glove box. Ball milling is carried out on a planetary ball mill, and an inert atmosphere is maintained throughout the ball milling process. The first step is to pre-grind the raw materials with a low-speed ball mill (120rpm), and the ball milling time is 60min to mix the materials evenly. The second step is to remove the ball mill, send it into a glove box, and scrape off the materials on the inner wall of the ball mill. In the third step, high-speed ball milling (550rpm) is performed forward for 15 minutes, stopped to cool for 5 minutes, and then reversed for 15 minutes, stopped to cool for 5 minutes, and repeated four times. In the fourth step, the ball milling jar after four times of ball milling is sent to the glove box to scrape off the material on the inner wall. In the fifth step, the third and fourth steps are repeated 8 times, and the ball milling is completed. In the glove box, the electrolyte powder after ball milling is poured into a mold and pressed into a disc with a diameter of 16mm and a thickness of 1.2mm at a pressure of 250Mpa. Then the electrolyte disc is placed in a tubular furnace, heated to 150℃ at a heating rate of 5℃ / min in an argon atmosphere, kept warm for 300 minutes, and then cooled naturally. The cooled material is placed in the ball milling jar again and pulverized by low-speed ball milling (120rpm). After sieving with a 300-mesh sieve, it is put into a bottle for standby use.
[0057] Example 6
[0058] This embodiment provides a Na7Si 0.2 Sn 0.3 Ge 0.5 The preparation method of S5Br solid electrolyte comprises the following steps:
[0059] Weigh 1.47gNa2S, 0.115g SiS2, 0.343g SnS2, 0.428g GeS2 and 0.646gNaBr raw materials in a stoichiometric ratio, pour them into a mortar and grind them to mix evenly, then pour the mixed raw materials into a 100mL ball mill. And put a total of 60g of ZrO2 balls with diameters of 4mm (20g), 6mm (20g), 8mm (10g), and 10mm (10g) into the jar, and the material ball mass ratio is 1:20. In order to ensure that there is no contact with air, the entire weighing, grinding and ball mill charging process are completed in a glove box. Ball milling is carried out on a planetary ball mill, and an inert atmosphere is maintained throughout the ball milling process. The first step is to pre-grind the raw materials with a low-speed ball mill (120rpm), and the ball milling time is 60min to mix the materials evenly. The second step is to remove the ball mill, send it into a glove box, and scrape the materials on the inner wall of the ball mill. In the third step, high-speed ball milling (550rpm) is performed forward for 15 minutes, stopped to cool for 5 minutes, and then reversed for 15 minutes, stopped to cool for 5 minutes, and repeated four times. In the fourth step, the ball milling jar after four times of ball milling is sent to the glove box to scrape off the material on the inner wall. In the fifth step, the third and fourth steps are repeated 8 times, and the ball milling is completed. In the glove box, the electrolyte powder after ball milling is poured into a mold and pressed into a disc with a diameter of 16mm and a thickness of 1.2mm at a pressure of 250Mpa. Then the electrolyte disc is placed in a tubular furnace, heated to 150℃ at a heating rate of 5℃ / min in an argon atmosphere, kept warm for 300 minutes, and then cooled naturally. The cooled material is placed in the ball milling jar again and pulverized by low-speed ball milling (120rpm). After sieving with a 300-mesh sieve, it is put into a bottle for standby use.
[0060] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.
Claims
1. A solid-state argyrodite electrolyte material, characterized in that: The chemical formula of the material is Na α M β S5X x , wherein M is one or more of Sb, Si, Sn, and Ge, X is one or more of F, Cl, Br, and I, and 6≤α≤8, 0<β≤1, and 0<x≤1.
2. The solid-state argyrodite electrolyte material according to claim 1, characterized in that: In the chemical formula, β=1, x=1.
3. The solid-state argyrodite electrolyte material according to claim 1, characterized in that: In the chemical formula, X is one or more of Cl, Br, and I.
4. A method for preparing the solid-state argyrodite electrolyte material according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) According to the chemical formula of the compound, synthesize Na α M β S5X x The required Na source compound, sulfide and halide are weighed and mixed, and then ball-milled and tableted to obtain compact tablets; (2) The compacted sheet is heat treated, cooled and then crushed to obtain the solid-state argyrodite electrolyte material.
5. The method for preparing the solid-state argyrodite electrolyte material according to claim 4, characterized in that: In step (1), the Na source compound includes Na2S, the sulfide includes at least one of SiS2, Sb2S3, SnS2, GeS2, and elemental sulfur, and the halide includes at least one of NaCl, NaBr, and NaI.
6. The method for preparing the solid-state argyrodite electrolyte material according to claim 4, characterized in that: In step (1), the mass ratio of the balls in the ball milling process is 1:(15-25).
7. The method for preparing the solid-state argyrodite electrolyte material according to claim 4, characterized in that: In step (1), the ball milling process comprises the following steps: low-speed ball milling at a speed of 100-140 rpm for 50-70 min; then high-speed ball milling at a speed of 500-600 rpm for 120-160 min; repeating low-speed ball milling and high-speed ball milling for 6-15 times; The ball milling process was carried out under an inert gas atmosphere.
8. The method for preparing the solid-state argyrodite electrolyte material according to claim 4, characterized in that: In step (1), the tabletting pressure is 150 Mpa-250 Mpa.
9. The method for preparing the solid-state argyrodite electrolyte material according to claim 4, characterized in that: In step (2), the heat treatment conditions are: heating to 150-250°C at 5-10°C / min and keeping the temperature for 180-300min.
10. A solid-state sodium battery, characterized in that: The structure of the battery comprises the solid-state argyrodite electrolyte material according to any one of claims 1 to 3 or the solid-state argyrodite electrolyte material prepared by the preparation method according to any one of claims 4 to 9, as well as a positive electrode and a negative electrode.