A halide solid-state electrolyte composite material with high air stability and mechanical enhancement, a preparation method thereof and a full solid-state battery

Abstract

The application provides a halide solid-state electrolyte composite with high air stability and mechanical enhancement, a preparation method thereof and a full solid-state battery, and relates to the technical field of full solid-state batteries. In view of the problems of the existing halide solid-state electrolyte, such as sensitivity to humidity, easy hydrolysis and insufficient mechanical strength, the application forms a continuous multi-layer uniform pore structure by uniformly dispersing mesoporous reinforcing material particles in the halide solid-state electrolyte matrix. The composite significantly improves the humidity resistance and mechanical properties while maintaining high ionic conductivity: after being exposed to a 50% relative humidity environment for 1 hour, the ionic conductivity retention rate is not less than 90%, and the release of harmful gases such as HCl is effectively inhibited. The preparation method comprises wet mixing, drying and molding of the halide matrix and the mesoporous material in an inert atmosphere, and the process is simple and suitable for large-scale production. The composite can effectively improve the environmental stability and cycle performance of the full solid-state battery.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a halide solid electrolyte composite material with high air stability and mechanical enhancement, its preparation method, and an all-solid-state battery. Background Technology

[0002] With the continuous development of all-solid-state battery technology, solid-state electrolyte materials, due to their high safety, high energy density, low leakage risk, and excellent mechanical strength, are gradually becoming an important development direction to replace traditional liquid electrolyte systems. Currently, mainstream solid-state electrolytes include oxide-based electrolytes (such as Li7La3Zr2O). 12 Li 1.5 Al 0.5 Ge 1.5 (PO4)3), sulfides (such as Li) 10 GeP2S 12 Materials such as Li6PS5Cl and halides (e.g., Li3InCl6) are widely used in the construction of next-generation all-solid-state lithium batteries. These materials each have their own characteristics and exhibit different advantages in terms of ionic conductivity, interfacial stability, and electrochemical window.

[0003] Among them, halide solid electrolytes (such as Li2MX4, Li3InX6, Li3OX and Li a MOX b Halogenated systems have attracted much attention in recent years. Compared to oxide electrolytes, halide systems typically exhibit higher room-temperature lithium-ion conductivity (some exceeding 10). -3 S cm -1 Furthermore, its relatively soft texture allows it to easily form close contact with electrode materials under lower pressure, reducing interfacial impedance. At the same time, compared to sulfide electrolytes, halide materials exhibit superior chemical and electrochemical stability to high-voltage oxide cathodes (such as lithium-rich manganese-based and lithium cobalt oxide), effectively suppressing interfacial side reactions and widening the battery's operating voltage window. This provides an important material foundation for realizing high-energy-density all-solid-state batteries.

[0004] However, despite the significant advantages of solid-state electrolytes in terms of theoretical performance, a key challenge remains in their practical applications—the chemical instability of the materials in air. For example, oxide electrolytes like Li7La3Zr2O... 12 For example, exposed surfaces readily react with water vapor and carbon dioxide in ambient temperature and humidity, generating alkaline byproducts such as LiOH and Li₂CO₃. This leads to an increase in electrode-electrolyte interface impedance, affecting the battery's rate performance and cycle life. Sulfide electrolytes, such as Li₂CO₃... 10 GeP2S 12Although Li6PS5Cl has high ionic conductivity and excellent film-forming properties, it readily reacts with oxygen and water vapor in the air, causing the material to decompose and release toxic gases such as H2S, while also forming non-conductive byproducts, which seriously restricts its processability and safety.

[0005] For halide solid electrolytes, environmental stability is also a prominent and complex issue. Halide materials are generally extremely sensitive to trace amounts of H₂O, O₂, and CO₂ in the environment. Taking the typical Li₃InCl₆ as an example, its crystal structure contains halide ions (Cl₂O₃, O₂, and CO₂). - Under humid conditions, halogen electrolytes are prone to hydrolysis, which may lead to the release of HCl gas and the formation of amorphous materials or insulating phases such as LiOH·H2O and In(OH)3. This process not only causes the loss of active lithium and a sharp decline in ionic conductivity, but the resulting acidic byproducts may also corrode current collectors and other battery components, posing safety hazards. Furthermore, some halide electrolytes (such as systems containing Zr and Hf) may oxidize or react with CO2 in air to form a carbonate layer, further hindering lithium-ion transport. These problems necessitate that the synthesis, storage, and battery assembly of halide electrolytes be carried out in a strictly controlled inert atmosphere (such as a glove box with a dew point below -40°C), significantly increasing the complexity of the production process and equipment costs, becoming one of the main bottlenecks restricting their large-scale application.

[0006] Besides chemical stability, the mechanical properties of halide electrolytes also need further optimization. Although their flexibility is beneficial for interfacial contact, during the preparation of composite cathodes, the significant mechanical property mismatch between the halide phase and high-modulus cathode active particles (such as NCM) leads to stress concentration in rigid cathode particles during external compression molding, causing them to crack. Simultaneously, the softer electrolyte regions may be insufficiently filled, forming pores and poor contact. This non-uniform microstructure increases the tortuosity of ion transport and may be exacerbated by volume changes during cycling, accelerating interfacial failure and capacity decay.

[0007] Existing patent solutions have significant limitations: Chinese patent CN119092805A relies on the low-temperature in-situ reaction of fluorine / borides on the surface to form a coating. The disadvantage is that the thickness and uniformity of the coating layer are difficult to control precisely, and it is an inert barrier layer that cannot actively adsorb moisture, and the interface may degrade during long-term cycling. Chinese patent CN121123378A uses metal ions to initiate surface polymerization. Its disadvantage is that it has high requirements for monomer type, solvent and metal ion specificity, narrow process window, limited ionic conductivity of the polymer layer generated, and mainly improves interface flexibility, with little contribution to improving bulk mechanical strength. Chinese patent CN120727807A focuses on the modification of the "electrolyte / cathode" interface on the positive electrode side. Its disadvantage is that the structure is complex, the preparation steps are cumbersome, and the problems of moisture absorption and mechanics of the electrolyte body are not solved, and the performance improvement is limited to the electrode interface.

[0008] Therefore, developing a technical solution that can simultaneously and effectively improve the environmental stability (especially moisture resistance) and mechanical integrity of halide solid electrolytes is crucial for their practical application. Existing improvement methods, such as surface coating, elemental doping, or polymer composites, often sacrifice other properties (such as ionic conductivity) while improving one performance, or suffer from problems such as complex processes, high costs, and limited effectiveness. The industry urgently needs a material design strategy that can construct a physicochemical barrier to isolate the electrolyte from environmental corrosion while maintaining its excellent ionic conductivity, and simultaneously act as a mechanically reinforcing phase to optimize the electrode microstructure, thereby achieving a synergistic improvement in performance. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a halide solid electrolyte composite material with enhanced moisture resistance and mechanical strength. By uniformly dispersing mesoporous reinforcing material particles in a halide solid electrolyte matrix, a continuous multilayer uniform pore structure is formed, which significantly improves the material's moisture stability and mechanical strength while maintaining excellent ion conductivity.

[0010] One of the objectives of this invention is to provide a halide solid electrolyte composite material with high air stability and mechanical enhancement.

[0011] The second objective of this invention is to provide a method for preparing the halide solid electrolyte composite material with high air stability and mechanical enhancement.

[0012] The third objective of this invention is to provide an all-solid-state battery, including the halide solid electrolyte composite material with high air stability and mechanical enhancement.

[0013] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a halide solid electrolyte composite material with high air stability and mechanical enhancement, comprising: a halide solid electrolyte matrix; and Mesoporous reinforcing material particles dispersed in the halide solid electrolyte matrix, wherein the mesoporous reinforcing material particles are encapsulated and uniformly dispersed within the halide solid electrolyte matrix.

[0014] Preferably, the halide solid electrolyte matrix is ​​selected from at least one of the following compounds: Compounds with the general formula Li2MX4, wherein M is selected from one of Mg, Ti, V, Cr, Mn, Fe, Co, Ni, and Cd, and X is selected from one of Cl and Br; Compounds with the general formula Li3InX6, wherein X is selected from Cl or Br; The general formula is Li 2+x Zr 1-x Compounds of Cl6, where 0 ≤ x < 1; Compounds with the general formula Li3OX, wherein X is selected from Cl or Br; The general formula is Li a MOX b Compounds in which M is selected from Nb, Al, Ta, and Zr, and X is selected from Cl and Br, where 1 ≤ a ≤ 2 and 2 ≤ b ≤ 6. Examples include LiNbOCl4, LiAlOCl2, LiTaOCl4, and Li... 1.75 Zr 0.5 Cl 4.75 wait.

[0015] Furthermore, the halide solid electrolyte composite material has one or more of the following properties: 1. Ionic conductivity ≥ 1×10 -3 S / cm, electronic conductivity ≤1.0×10 -8 S / cm; 2. The average particle size D50 ranges from 1.0 μm to 4.5 μm, and the particle size distribution width Span value (Span = (D90 - D10) / D50) ranges from 1.0 to 2.0; 3. After being exposed to an environment with a relative humidity of 50% for 1 hour, the ionic conductivity retention rate is not less than 90%.

[0016] Preferably, the mesoporous reinforcing material is selected from at least one of mesoporous silica, mesoporous carbon materials, mesoporous alumina, mesoporous zirconium oxide, mesoporous titanium dioxide, mesoporous metal-organic framework materials, and mesoporous polymer materials. More preferably, the mesoporous reinforcing material is mesoporous silica (such as SBA-15, MCM-41) or mesoporous carbon material (such as ordered mesoporous carbon CMK-3) with a specific surface area of ​​200 m². 2 / g to 1000m 2 / g, pore size from 2nm to 50nm, pore volume 0.2cm³ 3 / g to 1.5cm 3 / g.

[0017] Preferably, the mesoporous reinforcing material particles have a mass fraction of 0.5% to 10% in the composite material, and more preferably 1% to 5%.

[0018] Secondly, the present invention provides a method for preparing the above-mentioned halide solid electrolyte composite material, comprising one of the following methods: Method 1: The dried halide solid electrolyte matrix was mixed with mesoporous reinforcing material particles and ball-milled to obtain the halide solid electrolyte composite material.

[0019] Method 2: S1: In an inert atmosphere or vacuum environment, the halide solid electrolyte matrix and mesoporous reinforcing material particles are co-dispersed in an organic solvent and mixed to form a slurry; The organic solvent is selected from one or a mixture of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, and acetone. S2: The mixture is subjected to rotary evaporation to remove the organic solvent, and then dried to obtain a composite powder block; S3: Grind the composite powder block to obtain the halide solid electrolyte composite material.

[0020] Thirdly, the present invention provides an all-solid-state battery, comprising a positive electrode, a negative electrode and an electrolyte layer located between the positive electrode and the negative electrode, wherein the positive electrode or the electrolyte layer contains the aforementioned halide solid electrolyte composite material.

[0021] Preferably, the positive electrode is a composite positive electrode, comprising a positive electrode active material, a conductive agent, and the halide solid electrolyte composite material.

[0022] The present invention also relates to the use of the halide solid electrolyte composite material in improving the environmental stability and cycle performance of all-solid-state batteries.

[0023] Beneficial effects: 1) This invention introduces mesoporous materials (such as mesoporous SiO2 and mesoporous carbon) with high specific surface area and regular pore structure into a halide solid electrolyte. Utilizing their abundant pores and surface functional groups (such as Si–OH), these materials physically adsorb and chemically bond water molecules in the environment, significantly blocking direct contact between H2O and the electrolyte matrix. After exposure to 50% relative humidity (RH) for 1 hour, the ionic conductivity retention rate of this composite material can be increased to over 90%, while effectively suppressing the release of harmful gases such as HCl, greatly enhancing the material's environmental stability and processing safety.

[0024] 2) This invention utilizes the higher mechanical stiffness of mesoporous materials compared to halide matrices, dispersing them uniformly in the electrolyte as a mechanically reinforcing phase. This design optimizes the stress distribution of the composite cathode during the pressing process, alleviating stress concentration and particle cracking caused by modulus mismatch between the active material (such as NCM) and the electrolyte. This reduces the porosity of the composite electrode by more than 20%, resulting in denser interfacial contact and significantly improving the structural integrity of the electrode and its interfacial stability during long-term cycling.

[0025] 3) The physical mixing and composite process provided by this invention is simple to operate, operates under mild conditions, requires no complex chemical reactions, and is easy to scale up for production. By precisely controlling the type, pore size, specific surface area, and addition amount (preferably 1-5 wt%) of the mesoporous material, it is possible to achieve the intrinsic high ionic conductivity (>10) of the halide electrolyte without significantly impairing it. -3 S cm - Under the premise of ¹), the synergistic enhancement of moisture resistance and mechanical properties is achieved, providing a key material basis for the preparation of high-performance, high-reliability all-solid-state batteries.

[0026] The present invention has been described in detail above; however, the above embodiments are merely illustrative in nature and are not intended to limit the invention. Furthermore, this document is not limited to the foregoing prior art or the invention itself, or to any theory described in the following embodiments. Attached Figure Description

[0027] Figure 1 A schematic diagram of the composite material structure and its adsorbed water molecules; Figure 2 SEM image of Li3InCl6 halide electrolyte; Figure 3 The impedance spectrum is shown in Example 2. Detailed Implementation

[0028] The present invention will be further described below with reference to the embodiments. It should be noted that the following embodiments are provided for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0029] Unless otherwise specified, the raw materials, reagents, and methods used in the embodiments are all conventional raw materials, reagents, and methods in the art.

[0030] Example 1: Preparation of 1 wt% mesoporous SiO2 (SBA-15) composite Li3InCl6 electrolyte In a dry room with a dew point below -50°C, the halide solid electrolyte Li3InCl6 raw material was placed in a vacuum drying oven and dried at 120°C for 12 hours to completely remove physically adsorbed water. Mesoporous silica SBA-15 (specific surface area 600±50 m²) 2 The powder (7.5±0.5nm pore size) was vacuum dried at 200℃ for 24 hours for later use. Using an analytical balance with an accuracy of 0.1mg, 4.9000g of dried Li3InCl6 powder and 0.0500g of dried SBA-15 powder (mass ratio 98:1, i.e., SiO2 content approximately 1wt%) were weighed and placed in a 50mL zirconia ball mill jar. Zirconia grinding balls with diameters of 5mm and 10mm were added to the jar, with a ball-to-powder mass ratio of 30:1. The jar was sealed and removed from the glove box, then mounted on a planetary ball mill. Under an argon protective atmosphere, the ball mill speed was set to 400rpm, and the mill was run forward for 15 minutes, then paused for 5 minutes (to prevent overheating). This constituted one cycle. A total of 8 cycles were performed, with a total effective milling time of 2 hours. After milling, the jar was transferred back to the glove box, opened, and the grinding balls and composite powder were separated using a 200-mesh sieve. The collected uniform composite powder.

[0031] Example 2: Preparation of 2wt% mesoporous SiO2 (SBA-15) composite Li3InCl6 electrolyte In a drying chamber, 4.8000 g of dried Li3InCl6 powder and 0.1000 g of dried SBA-15 powder (mass ratio 96:2, i.e., SiO2 content 2wt%) were weighed and placed in a ball mill jar. The same ball milling parameters as in Example 1 were used for compounding (ball-to-powder ratio 30:1, 400 rpm, 15 minutes run / 5 minutes pause, 8 cycles, total 2 hours). The compounded powder was collected.

[0032] Example 3 Preparation of 3wt% mesoporous SiO2 (SBA-15) composite Li3InCl6 electrolyte Weigh 4.7000g of Li3InCl6 and 0.1500g of SBA-15 (SiO2 content 3wt%), and follow the same procedure as in Example 1. Collect the composite powder.

[0033] Example 4: Preparation of 5wt% mesoporous SiO2 (SBA-15) composite Li3InCl6 electrolyte Weigh 4.5000g of Li3InCl6 and 0.2500g of SBA-15 (SiO2 content 5wt%), and follow the same procedure as in Example 1. Collect the composite powder.

[0034] Example 5 Preparation of 2wt% mesoporous carbon (CMK-3) composite Li3InCl6 electrolyte Ordered mesoporous carbon CMK-3 (specific surface area 1200±100m²) 2 / g, pore size 4.0±0.3nm) at 250℃, high vacuum (<10 -3 The material was degassed at 12 hours under high pressure (Pa) to remove adsorbed gases and impurities. In a glove box, 4.8000 g of dry Li3InCl6 and 0.1000 g of treated CMK-3 powder were accurately weighed. To prevent structural damage to the carbon material during high-speed ball milling, milder milling conditions were used: ball-to-material ratio 20:1, rotation speed 300 rpm, 10-minute run / 5-minute pause, for a total of 12 cycles, with a total effective milling time of 2 hours. The resulting black composite powder was collected.

[0035] Example 6 Preparation of 2wt% mesoporous SiO2 (MCM-41) composite Li2ZrCl6 electrolyte Li₂ZrCl₆ powder was synthesized and dried according to standard methods. Mesoporous silica MCM-41 (specific surface area 1000±80 m²) was used. 2 / g (pore size 3.0±0.2nm), vacuum dried at 200℃. 4.8000g Li₂ZrCl₆ and 0.1000g MCM-41 were weighed. The same ball milling parameters as in Example 1 were used (400rpm, 2 hours). The composite powder was collected.

[0036] Example 7 Preparation of 2wt% mesoporous SiO2 (SBA-15) composite Li3YCl6 electrolyte Li3YCl6 powder was used. SBA-15 was treated the same as before. 4.8000 g of Li3YCl6 and 0.1000 g of SBA-15 were weighed. The same ball milling parameters as in Example 1 were used. The composite powder was collected.

[0037] Example 8: Wet mixing preparation of 2wt% mesoporous SiO2 (SBA-15) composite Li3InCl6 electrolyte Precursor slurry preparation: In a glove box, disperse 0.1000 g of SBA-15 in 20 mL of anhydrous acetonitrile and sonicate for 30 minutes to form a uniform dispersion. Add 4.8000 g of Li3InCl6 powder to the dispersion and stir continuously for 6 hours at room temperature using a magnetic stirrer. Transfer the suspension to a rotary evaporator and slowly evaporate the acetonitrile to dryness under reduced pressure in a 40°C water bath. Dry the resulting lumps under vacuum at 80°C for 12 hours in a glove box. Gently grind the dried lumps in an agate mortar and pass them through a 200-mesh sieve to obtain the composite powder.

[0038] Comparative Example 1: Original Li3InCl6 Electrolyte Take 5.0000g of dried Li3InCl6 powder from the same batch as in Example 1, without adding any modifying materials. To eliminate the possible influence of the mechanical ball milling process, place the Li3InCl6 powder in the same ball mill jar, add an equal amount of grinding balls, and perform blank ball milling under the same conditions (400 rpm, 2 hours) to obtain the sample.

[0039] Comparative Example 2: Preparation of Li3InCl6 electrolyte with LiF / Li2O coating on its surface Preparation of the coating precursor solution: In a glove box, weigh 0.1000 g of lithium tetrafluoroborate (LiBF4) and dissolve it in 20 mL of anhydrous acetonitrile. Stir magnetically for 30 minutes until completely dissolved. Weigh 4.9000 g of dried Li3InCl6 powder and place it in a round-bottom flask. While stirring, add the LiBF4 / acetonitrile solution dropwise to the powder. After the addition is complete, continue stirring for 2 hours to ensure uniform wetting by the precursor solution. Remove the acetonitrile solvent by rotary evaporation at 40 °C. Transfer the resulting wet powder to an alumina crucible and place it in a tube furnace. Under continuous flow of high-purity argon (100 sccm), heat to 120 °C at 5 °C / min and hold for 1 hour to allow LiBF4 to decompose in situ on the Li3InCl6 surface, forming a coating layer containing Li, F, O, and B. After the process is complete, allow it to cool naturally to room temperature in an argon flow. Remove the powder, grind it slightly, and then sieve it to obtain electrolyte powder with a surface coating.

[0040] Comparative Example 3: Preparation of 2wt% nonporous nano-SiO2 composite Li3InCl6 electrolyte Non-porous nano-silica (specific surface area 200±20m²) produced by vapor phase method 2 / g, particle size approximately 20nm, no obvious mesoporous structure), dried under the same conditions as SBA-15. 4.8000g Li3InCl6 and 0.1000g nonporous nano-SiO2 were weighed and mixed using the same ball milling process as in Example 1. The composite powder was collected.

[0041] Comparative Example 4: 2 wt% SBA-15 complex of simple physical mixing (without ball milling) Weigh 4.8000g of Li3InCl6 and 0.1000g of SBA-15 and place them directly into a glass bottle. Use a planetary oscillator to intermittently mix at maximum speed in a dry room for 30 minutes, and collect the powder after mixing by gentle shearing.

[0042] Comparative Example 5: Original Li₂ZrCl₆ Electrolyte Take dry Li2ZrCl6 powder and perform blank ball milling treatment in the same way as Comparative Example 1.

[0043] Comparative Example 6: Preparation of Li3InCl6 composite material with 2wt% micron-sized LiF powder Weigh 4.8000 g of Li3InCl6 and 0.1000 g of LiF powder with an average particle size of 5 μm. Perform the same ball milling process as in Example 2. Collect the composite powder.

[0044] Comparative Example 7: Over-coated (10wt% SBA-15) composite Li3InCl6 electrolyte Weigh 4.0000g of Li3InCl6 and 0.4444g of SBA-15 (SiO2 content 10wt%). Collect the composite powder using the same ball milling process as in Example 1.

[0045] It should be noted that the above is only one method for synthesizing composite materials. This patent does not limit the specific synthetic route of the electrolyte material, which can be obtained by any method. Alternatively, commercially available electrolyte materials can be directly purchased for further processing.

[0046] Test case The electrolyte materials in Examples 1-8 and Comparative Examples 1-7 were exposed to an environment with 50% relative humidity for 1 hour. Before and after exposure, stainless steel|electrolyte|stainless steel symmetric batteries were assembled in a glove box. Their ionic conductivity was measured by electrochemical impedance spectroscopy, and their electronic conductivity was tested by DC steady-state polarization method. Simultaneously, a customized sealed detection system was used, employing an infrared gas analysis module to monitor the concentration of HCl gas released during exposure online. Table 1 shows the initial ionic conductivity, ionic conductivity after exposure, ionic conductivity retention rate, and HCl release for Examples 1-9 and Comparative Examples 1-7. It can be seen that Example 2, while maintaining a high initial conductivity (1.49 mS / cm), achieved an optimal 83.9% ionic conductivity retention rate and extremely low HCl release (10 ppm), indicating that 2 wt% is the performance balance point. Excessive addition, while improving the material's air stability, has a significant impact on its ionic conductivity.

[0047] Table 1. Initial ionic conductivity, electronic conductivity, ionic conductivity retention rate, and HCl release amount for Examples 1-8 and Comparative Examples 1-7.

[0048] Nanoindentation mechanical property tests were performed on Examples 2 and 5, and Comparative Examples 1, 2, 3, and 6. Additionally, 70 wt% electrolyte powder, 25 wt% NCM811 active material, and 5 wt% acetylene black were manually ground and mixed in a mortar for 5 minutes. 100 mg of the mixture was pressed into composite positive electrode sheets with a diameter of 10 mm. The porosity was measured using a mercury porosimeter. The results are shown in Table 2. After introducing the mesoporous material, the hardness and modulus of Example 2 showed a significant mechanical enhancement compared to the original electrolyte material. Thanks to the enhanced mechanical properties, the composite porosity of Example 2 was significantly lower than that of Comparative Example 1, demonstrating its more effective ability to improve stress issues, optimize electrode particle contact, and construct a more continuous ion transport network.

[0049] Table 2 Mechanical properties and porosity of Examples 2 and 5 and Comparative Examples 1, 2, 3 and 6

[0050] Using samples from Examples 2, 5, and 8, and Comparative Examples 1 and 2 as solid electrolytes, 2032-type coin-type all-solid-state batteries were assembled with an NCM811 composite positive electrode (active material loading of approximately 20 mg / cm²) and a lithium-steel alloy (Li-In) negative electrode. The batteries were tested at 60°C and 2.8–4.3 V (vs. Li-In / Li + The voltage window was used for testing. The results are shown in Table 3. The material in Example 2 maintained a capacity retention of 88.5% after 50 cycles. This was due to its excellent bulk moisture resistance, which reduced persistent interfacial side reactions, and its enhanced mechanical properties, which stabilized the electrode / electrolyte interface contact and effectively suppressed contact failure during cycling.

[0051] Table 3. Initial discharge capacity at 0.1C, cycle retention at 1C (50 cycles), and discharge capacity at 2C rate for Examples 2, 5, 8 and Comparative Examples 1, 2.

[0052] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and substance defined by the claims of the present invention; and such modifications or substitutions are still within the scope defined by the claims of the present invention.

Claims

1. A halide solid electrolyte composite material with high air stability and mechanical enhancement, characterized in that, include: Halide solid electrolyte matrix; as well as Mesoporous reinforcing material particles dispersed in the halide solid electrolyte matrix, wherein the mesoporous reinforcing material particles are encapsulated and uniformly dispersed within the halide solid electrolyte matrix.

2. The halide solid electrolyte composite material with high air stability and mechanical enhancement according to claim 1, characterized in that, The halide solid electrolyte matrix is ​​selected from at least one of the following compounds: Compounds with the general formula Li2MX4, wherein M is selected from one of Mg, Ti, V, Cr, Mn, Fe, Co, Ni, and Cd, and X is selected from one of Cl and Br; Compounds with the general formula Li3InX6, wherein X is selected from Cl or Br; The general formula is Li 2+x Zr 1-x Compounds of Cl6, where 0 ≤ x < 1; Compounds with the general formula Li3OX, wherein X is selected from Cl or Br; The general formula is Li a MOX b The compounds, wherein M is selected from one of Nb, Al, Ta, and Zr, and X is selected from one of Cl and Br, 1≤a≤2, 2≤b≤6.

3. The halide solid electrolyte composite material with high air stability and mechanical enhancement according to claim 1, characterized in that, The mesoporous reinforcing material is selected from at least one of mesoporous silica, mesoporous carbon materials, mesoporous alumina, mesoporous zirconium oxide, mesoporous titanium dioxide, mesoporous metal-organic framework materials, and mesoporous polymer materials; More preferably, the mesoporous reinforcing material is selected from at least one of SBA-15, MCM-41, and CMK-3, and has a specific surface area of ​​200 m². 2 / g to 1000m 2 / g, with pore sizes ranging from 2nm to 50nm.

4. The halide solid electrolyte composite material with high air stability and mechanical enhancement according to claim 1, characterized in that, The mesoporous reinforcing material particles have a mass fraction of 0.5% to 10% in the composite material, preferably 1% to 5%.

5. The halide solid electrolyte composite material with high air stability and mechanical enhancement according to claim 1, characterized in that, The ionic conductivity of the halide solid electrolyte composite material is ≥1×10⁻⁶. -3 S / cm, electronic conductivity ≤1.0×10 -8 S / cm.

6. The halide solid electrolyte composite material with high air stability and mechanical enhancement according to claim 1, characterized in that, The average particle size D50 of the halide solid electrolyte composite material ranges from 1.0 μm to 4.5 μm, and the particle size distribution width Span value ranges from 1.0 to 2.

0.

7. The halide solid electrolyte composite material with high air stability and mechanical enhancement according to claim 1, characterized in that, The halide solid electrolyte composite material retains an ionic conductivity of no less than 90% after being exposed to an environment with a relative humidity of 50% for 1 hour.

8. A method for preparing a halide solid electrolyte composite material with high air stability and mechanical enhancement as described in any one of claims 1-7, characterized in that, Includes one of the following methods: Method 1: The dried halide solid electrolyte matrix was mixed with mesoporous reinforcing material particles and ball-milled to obtain the halide solid electrolyte composite material. Method 2: S1: In an inert atmosphere or vacuum environment, the halide solid electrolyte matrix and mesoporous reinforcing material particles are co-dispersed in an organic solvent and mixed to form a slurry; S2: The mixture is subjected to rotary evaporation to remove the organic solvent, and then dried to obtain a composite powder block; S3: Grind the composite powder block to obtain the halide solid electrolyte composite material.

9. The preparation method according to claim 8, characterized in that, The organic solvent is selected from one or more of acetonitrile, tetrahydrofuran, N-methylpyrrolidone, dimethyl sulfoxide, and acetone.

10. An all-solid-state battery, characterized in that, It includes a positive electrode, a negative electrode, and an electrolyte layer located between the positive electrode and the negative electrode, wherein the positive electrode or the electrolyte layer contains the halide solid electrolyte composite material according to any one of claims 1-7.

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