A novel oxyhalide electrolyte and its preparation method and application

Abstract

The present invention discloses a novel oxohalide electrolyte, its preparation method and application, which is an amorphous-UCl3 composite structure with a chemical general formula of: Li b M y Al a O3X b+3a+3y‑6 , where: M is at least one element selected from La, Ce, Pr, Sm, Nd, U; X is at least one element selected from F, Cl, Br, I; 0 < b ≤ 6, 0.1 ≤ y ≤ 7, 0 < a. The oxohalide solid electrolyte of the present invention can combine the UCl3-type structure with the amorphous structure to exert the advantages of both. This oxohalide electrolyte has a high ionic conductivity (>1 mS / cm) at room temperature, and its components are adjustable. It expands the family of halide electrolytes, including but not limited to applications in lithium-ion batteries, exhibits good electrochemical performance, and the preparation process is relatively simple, which is conducive to expanding production.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a novel oxyhalide electrolyte and a preparation method and application thereof. Background Art

[0002] With the rapid development of renewable energy, the research and development of high energy density and high power energy storage devices has attracted much attention. Conventional lithium-ion batteries (LIBs) composed of organic liquid electrolytes are energy storage devices that have been successfully commercialized for decades. Despite continuous improvements, traditional LIB technology still has safety issues such as the flammability of liquid electrolytes and separators. In recent years, the repeated occurrence of fire accidents caused by spontaneous combustion and explosion of electric vehicle batteries has triggered people's in-depth thinking on safety. There is an urgent need for an energy storage device with advantages such as high safety and high energy density. All-solid-state batteries, because their components are all solid-phase, greatly reduce the risk of thermal runaway of the battery, and there is no problem of violent decomposition in high and low temperature environments. They have excellent safety and a wide operating temperature range. Due to the above advantages, all-solid-state batteries have become a research hotspot in the field of energy storage. As a key component of all-solid-state batteries, the research and development of solid-state electrolytes is crucial.

[0003] At present, inorganic solid electrolytes mainly include sulfide solid electrolytes, oxide solid electrolytes and halide solid electrolytes. For example, sulfide electrolytes (Li6PS5Cl) usually exhibit high ionic conductivity (maximum >10mS cm -1 ), but it has a narrow electrochemical window (~2.6V vs.Li / Li + ) and is very sensitive to moisture. It can react with trace amounts of water in the air to produce toxic H2S gas, which damages the overall safety of the battery (Chem. Mater. 28, 266-273 (2016); Nature Communications (2022) 13, 7237). Another major type of solid electrolyte is oxide electrolyte, such as Li7La3Zr2O 12 (The maximum ionic conductivity at 27°C is 1.8 mS cm -1 ) has good electrochemical oxidation stability, but its mechanical properties are very brittle, which makes it challenging to assemble all-solid-state batteries with oxide solid electrolytes without hot pressing sintering conditions (Nat. Mater. (2017) 16, 572-579; Nat. Energy (2019) 4, 475-483).

[0004] Recently, halide solid electrolytes have become strong competitors because they combine the dual advantages of sulfide and oxide electrolytes, namely good deformability, sinterability and good (electro)chemical stability. Asano et al. reported that triangular Li3YCl6 prepared by mechanochemical method showed moderate Li + Conductivity, 0.51mS cm -1 , and even when an uncoated LiCoO2-based cathode is used in combination with a Li-In anode, it shows good performance in all-solid-state batteries (Adv. Mater. (2018) 30, 1803075). Kai Wang et al. studied an economical Li2ZrCl6 electrolyte that can simultaneously achieve high ionic conductivity (0.81 mS cm at room temperature) -1 ), deformability and compatibility with 4V-class cathode materials. When matched with single crystal LiNi 0.8 Mn 0.1 Co 0.1 When O2 is the positive electrode and Li-In is the negative electrode, it can release 150mAh g -1 And stably cycled for 200 cycles (Nature Communications (2021) 12, 441020). These results have promoted the research of halide electrolytes. Halide electrolytes have been able to cycle batteries, and halide electrolytes are currently prepared by wet chemical methods, high-energy ball milling methods, and high-temperature melting methods. However, there is still a need to further improve the ionic conductivity (~1mS cm -1 ) and broaden the electrochemical window; and part of the above-mentioned operation steps are too cumbersome, and the other part is very energy-consuming and not easy to develop on a large scale. How to obtain solid electrolytes using a simple production method becomes very critical. The development of a new type of solid electrolyte technology is very necessary for the realization of highly safe all-solid-state battery applications. The newly emerged amorphous halide solid electrolytes exhibit excellent electrochemical properties, and UCl3-type structural materials have attracted great attention from researchers due to the presence of fast ion transport channels along the c-axis. How to use a simple method to effectively combine the two structures has become a major difficulty in the development of solid electrolyte materials. Therefore, the development of a new type of solid electrolyte technology is very necessary for the realization of highly safe all-solid-state battery applications. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a new oxyhalide electrolyte and its preparation method and application, which can combine the UCl3 type structure with the amorphous structure to jointly promote the transport of ions. The present invention provides such a new oxyhalide electrolyte and its preparation method and application, and the oxyhalide solid electrolyte has a conductivity of >1mS cm at room temperature. -1The high ionic conductivity and large adjustability of the components have expanded the family of oxyhalide electrolytes, including but not limited to applications in lithium-ion batteries. It can exhibit good electrochemical properties and the preparation process is relatively simple, which is conducive to expanding production.

[0006] The present invention is achieved through the following technical solutions:

[0007] A new type of oxyhalide electrolyte, whose structure is an amorphous-UCl3 composite structure, and its chemical formula is: Li b M y Al a O3X b+3a+3y-6 ,in:

[0008] M includes at least one element selected from La, Ce, Pr, Sm, Nd, and U;

[0009] X includes at least one element selected from F, Cl, Br, and I;

[0010] X is at least one element selected from F, Cl, Br, and I;

[0011] 0 <b≤6,0.1≤y≤7,0<a。

[0012] Preferably, in order to improve the ionic conductivity and deformability of the solid electrolyte, X can be Cl, and the above composition formula can be written as Li b M y Al a O3Cl b+3a+3y-6 ;

[0013] Preferably, in order to expand the raw material selectivity of this type of new solid electrolyte, the M element can be one of La, Ce, Pr, Sm, Nd, U, or a combination of several of them in different proportions.

[0014] Preferably, the diffraction image of Cu Kα rays of the oxyhalide electrolyte mainly shows a hexagonal UCl3 type structure.

[0015] Further optionally, 1≤b≤4, in which case the ionic conductivity of the obtained oxyhalide solid electrolyte is higher.

[0016] In the present invention, the oxyhalide electrolyte has a hexagonal UCl3-type structure as its main structure, which provides a large one-dimensional fast lithium-ion transport channel, advantageously ensuring high lithium-ion transport characteristics. Furthermore, since oxygen has a greater electronegativity than chlorine, the introduction of oxygen into the chloride electrolyte helps increase oxidative stability, thereby improving the overall electrochemical window of the electrolyte.

[0017] Further optionally, the oxyhalide electrolyte includes a first crystal phase, having a double diffraction peak at 2θ=23.6°±0.5° to 2θ=24.7°±0.5°; and a single diffraction peak at 2θ=13.48°±0.7°; and the space group of the first crystal phase is P63 / m;

[0018] and / or, the oxyhalide electrolyte comprises an amorphous phase;

[0019] And / or, the oxyhalide electrolyte includes a second crystal phase and has a diffraction peak at 2θ=30.08°±0.5°.

[0020] The oxyhalide electrolyte provided by the present invention has a first crystalline phase. When X-ray diffraction is measured using Cu Kα radiation, a double diffraction peak is observed at positions 2θ = 23.6° ± 0.5° to 2θ = 24.7° ± 0.5°. In addition, a strong single diffraction peak is observed at 2θ = 13.48° ± 0.7°. The space group of the first crystalline phase is P63 / m. More preferably, the peak intensity ratio between the double diffraction peaks is 0.2 to 3.

[0021] The oxyhalide electrolyte provided by the present invention has a second crystal phase. In an X-ray diffraction test using Cu Kα rays, it contains the second crystal phase and has a certain diffraction peak at the position of 2θ=30.08°±0.5°, which belongs to the second crystal phase.

[0022] The oxyhalide electrolyte provided by the present invention has a first crystal phase as the main crystal phase, and the second crystal phase can be characterized by using the crystal phases of other halide lithium salts; in addition, it can also contain certain amorphous substances.

[0023] The oxyhalide electrolyte provided by the present invention may have a certain degree of flexibility, which is conducive to its application in the assembly of all-solid-state batteries, or the design of new all-solid-state battery devices, or reducing the pressure value required for assembling all-solid-state batteries at this stage.

[0024] The appearance morphology of the oxyhalide electrolyte provided by the present invention is not limited, for example, granular, thin film, layered, agglomerated, nanostructured, porous, etc.

[0025] The size of the oxyhalide electrolyte provided by the present invention is not limited and can be micrometer-scale or nanometer-scale.

[0026] In the present invention, the oxyhalide electrolyte has good stability to the positive electrode material and can be used as the electrolyte on the positive electrode side. At the same time, since it continues the excellent deformability of the oxyhalide electrolyte, it can be in close contact with the positive electrode particles, thereby realizing a rapid interfacial mass transfer process.

[0027] A method for preparing a novel oxyhalide electrolyte, used to prepare the novel oxyhalide electrolyte mentioned above, comprising the steps of:

[0028] Under the protection of an inert atmosphere, metal halide, inorganic lithium salt, aluminum chloride and inorganic metal oxide are mixed and subjected to heat treatment to obtain an oxyhalide electrolyte.

[0029] The inorganic metal oxide preferably includes antimony oxide.

[0030] Further optionally, the heat treatment temperature is 100° C.-800° C., and the heat treatment time is 50 min-600 min.

[0031] In the present invention, the mixed raw materials are placed in a heating device for heat treatment; the heating device can be a resistance heating furnace.

[0032] In the present invention, the mixing process can be carried out in a variety of ways, including mechanical methods such as mortar grinding and jet milling, mechanochemical methods such as low-energy mechanical ball milling and high-energy mechanical ball milling, and other methods can also be used to pre-mix the raw materials. Preferably, grinding and mechanical ball milling are used for mixing.

[0033] Further optionally, when the mixing process adopts mechanical ball milling, the following settings are made:

[0034] The ratio of ball milling beads to raw materials is 2 to 120:1;

[0035] and / or, the ball milling time is 24 h to 80 h;

[0036] And / or, the ball milling speed is 100 rpm-600 rpm.

[0037] Further optionally, a pressing step is further included after the mixing treatment and before the heat treatment.

[0038] The premixed raw materials can be selectively formed under pressure into any desired shape, such as square or round. The resulting shape and size can be varied and unlimited. The pressing step is optional; if used, the pressure range for pressurization is 100-5000 psi.

[0039] Preferably, the preparation method of the oxyhalide electrolyte of the present invention includes a premixing-heat treatment step. First, the prepared raw materials are premixed; second, the mixed raw materials are selectively pressed or directly processed into the next step; finally, after the previous steps are completed, a heat treatment process is performed to obtain a halide solid electrolyte with a high ionic conductivity.

[0040] Application of the above-mentioned novel oxyhalide electrolyte or the electrolyte prepared by the above-mentioned method for preparing the novel oxyhalide electrolyte in the field of batteries.

[0041] The oxyhalide electrolyte provided by the present invention can be used in any component of a battery. More preferably, it can be used in the positive electrode, negative electrode, electrolyte, interface layer, modification layer, protective layer, etc., and / or in any component of a doped or coated battery.

[0042] If used on the positive electrode side, it can be used to improve positive electrode materials and further applied in all-solid-state batteries, semi-solid-state batteries, or liquid batteries. If used as an electrolyte, it can be used in all-solid-state lithium batteries. All-solid-state batteries can be divided into positive electrode active materials, solid electrolytes, and negative electrode materials.

[0043] A battery comprises the above-mentioned novel oxyhalide electrolyte or an electrolyte prepared by the above-mentioned method for preparing the novel oxyhalide electrolyte.

[0044] In all-solid-state lithium battery applications, cathode active materials include lithium-containing transition metal oxides used in lithium-ion batteries, such as Li(NiCoAl)O2, Li(NiCoMn)O2, and LiCoO2, as well as transition metal fluorides, polyanionic materials, fluorinated polyanionic materials, transition metal sulfides, transition metal oxysulfides, and transition metal oxynitrides. The above-mentioned cathode materials can also undergo secondary improvement treatments, such as coating treatment, doping strategies, and interface engineering to enhance the stability and specific capacity of the materials. These materials all have good electrochemical properties and play an important role as cathodes in lithium-ion batteries.

[0045] In order to enable all-solid-state batteries to exhibit their excellent performance, such as electrochemical stability, large charge and discharge characteristics, efficient ion transport, etc., when assembling solid-state batteries, in addition to the positive electrode active material, negative electrode material and electrolyte of the present invention described above, at least one other type of electrolyte should be included. There is no restriction on the state of other electrolytes, which can be solid, gel, or liquid, as well as a mixture of these three types.

[0046] Preferably, from the perspective of the safety of all-solid-state lithium batteries, the positive electrode active material can be selected from lithium manganate positive electrode materials LiNi 0.88 Mn 0.06 Co 0.06 For O2, the negative electrode material can be a lithium alloy. Other electrolytes can be solid oxide electrolytes, sulfide electrolytes, halide electrolytes, etc.

[0047] The present invention has the following advantages and beneficial effects:

[0048] 1. The oxyhalide electrolyte proposed in the present invention is a solid electrolyte with a UCl3 structure. Currently, a small number of UCl3 structure-type solid electrolytes and oxyhalide solid electrolytes have appeared, but there has been no public report on this type of new halide electrolyte that combines the advantages of the two.

[0049] 2. The oxyhalide electrolyte provided by the present invention has great composition adjustability, low raw material prices, and has the potential for market application.

[0050] 3. The oxyhalide electrolyte provided by the present invention has high lithium ion conductivity, about 1mS cm -1 , which can achieve rapid lithium ion migration and low electronic conductivity, ensuring ion conduction while blocking electrons. This halide electrolyte shows good chemical inertness to the positive electrode active material. All-solid-state batteries assembled using this type of solid electrolyte exhibit high capacity, greater than 1mAh, and can achieve large-capacity batteries in high-load applications.

[0051] 4. Compared with the existing technology, the preparation method of the oxyhalide electrolyte provided by the present invention has obvious advantages, which are mainly reflected in the simple operation steps, wide applicability, and further application prospects of large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0053] Figure 1 This is the X-ray diffraction pattern of the oxyhalide electrolyte of Example 1 (1-Li-La-Al-O-Cl) of the present invention.

[0054] Figure 2 This is the impedance diagram of the oxyhalide electrolyte of Example 1 (1-Li-La-Al-O-Cl) of the present invention at room temperature.

[0055] Figure 3 This is the X-ray diffraction pattern of the oxyhalide electrolyte of Example 2 (2-Li-Ce-Al-O-Cl) of the present invention.

[0056] Figure 4 This is an impedance diagram of the oxyhalide electrolyte of Example 2 (2-Li-Ce-Al-O-Cl) of the present invention at room temperature.

[0057] Figure 5 This is the charge and discharge curve of the oxyhalide electrolyte of Example 1 (1-Li-La-Al-O-Cl) of the present invention at room temperature.

[0058] Figure 6This is a diagram of the electrochemical performance of the oxyhalide electrolyte of Example 2 (2-Li-Ce-Al-O-Cl) of the present invention at room temperature. DETAILED DESCRIPTION

[0059] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0060] Performance Testing

[0061] X-ray diffraction test: using an X-ray diffractometer under laboratory conditions, using copper Kα rays, wavelength Select the flatbed mode test.

[0062] Ionic conductivity test: When performing the ionic conductivity test, the EC-Lab electrochemical workstation is used to perform the AC impedance test method. The mold battery required for the test is composed of stainless steel / electrolyte material / stainless steel. The specific test steps are as follows: First, a certain mass (for example, 200 mg) of electrolyte material is weighed under an inert atmosphere and placed in a mold battery with a diameter of 10 mm. Subsequently, the electrolyte material is cold-pressed into a disc with a diameter of 10 mm under a pressure of 350 MPa. The area of the electrolyte disc is recorded as S, and the pressure is maintained for 30 seconds. The thickness of the electrolyte sheet is measured using a high-precision vernier caliper and recorded as L. The temperature of the conventional ionic conductivity test is 25°C, and the calculation formula is σ=L / (R*S), where L is the thickness of the solid electrolyte disc after cold pressing, S is the area of the electrolyte disc, and R is the impedance of the electrolyte material measured by the AC impedance method. In addition, after the electrolyte material is assembled into a battery, the electrochemical performance test of the all-solid-state battery will be carried out to explore its electrochemical performance.

[0063] Assembly and testing of all-solid-state batteries: The positive electrode material of the all-solid-state battery uses a nickel-cobalt-manganese ternary positive electrode material (NCM811), while the negative electrode uses a Li-In alloy. On the positive electrode side, the oxygen-containing halide electrolyte material prepared in the above example is used, while on the negative electrode side, a traditional sulfide electrolyte material (Li6PS5Cl) is selected. When assembling the all-solid-state battery, appropriate pressure is applied to each layer of the material.

[0064] An embodiment of the present invention provides a novel halide electrolyte, wherein the solid electrolyte comprises Li, M, Al, O, and X elements, wherein M is selected from at least one element of La or Ce, and the expression can be Li b M y Al a O3X b+3a+3y-6, the synthesis of this type of solid electrolyte mainly uses the premixing-heat treatment technology. b M y Al a O3Cl b+3a+3y-6 The synthesis process requires the preparation of raw materials. The raw materials used in the present invention can be obtained from the market through regular channels and do not require further special purification. The obtained raw materials can be mixed in one of a variety of ways, such as physical methods or chemical methods, and finally subjected to heat treatment technology to obtain the final product.

[0065] Example 1

[0066] This embodiment provides a novel oxyhalide electrolyte, and the specific preparation method is as follows:

[0067] The raw material powders were selected to have a mass of 0.302g, 0.385g, 1.286g, and 0.876g respectively of lithium chloride, lanthanum chloride, aluminum chloride, and antimony oxide, all of which had a purity greater than 99.9%, and were thoroughly mixed in a container. Ball milling was used for mixing for more than 24 hours. After thorough mixing, the mixture was transferred to an alumina crucible and heat-treated at 350°C under a nitrogen atmosphere using a heating device, thereby preparing a solid electrolyte material containing a crystalline phase of Li, La, Al, O, and Cl elements, as described in Example 1, and recorded as Example 1 (1-Li-La-Al-O-Cl).

[0068] The crystal structure of the solid electrolyte obtained in Example 1 was analyzed by X-ray diffraction. Figure 1 As shown, Example 1 shows good crystallization characteristics. The first crystalline phase belongs to the hexagonal system, P63 / m space group, and has diffraction peaks at 23.778° and 24.482°. When the raw materials are not fully mixed, a second crystalline phase of some LiCl phase will appear. The LiCl belongs to the cubic system and is the Fm-3m space group. Further, some of its diffraction peaks are located at 30.007°, 34.882°, and 50.167°. The amorphous content of the sample was further tested using the internal standard method, and the amorphous content was 61.4%.

[0069] The ionic conductivity of the solid electrolyte obtained in Example 1 is as follows: Figure 2 As shown, the ionic conductivity was found to be 1.2 mS / cm.

[0070] Example 2

[0071] This embodiment provides a novel oxyhalide electrolyte, and the specific preparation method is as follows:

[0072] The raw material powders were selected to have a mass of 0.255 g, 0.595 g, 1.448 g, and 0.703 g respectively of lithium chloride, cerium chloride, aluminum chloride, and antimony oxide. The purity of the above substances was greater than 99.9%, and they were fully mixed in a container. Ball milling was used for mixing for more than 24 hours. After being fully mixed, the mixture was transferred to an alumina crucible and heat-treated at 350° C. under a nitrogen atmosphere using a heating device. Thus, a solid electrolyte material containing a crystalline phase of Li, Ce, Al, O, and Cl elements was prepared in Example 2, which was recorded as Example 2 (2-Li-Ce-Al-O-Cl).

[0073] The crystal structure of the solid electrolyte described in Example 2 was analyzed by X-ray diffraction. Figure 1 As shown, Example 2 exhibits relatively high crystallinity, with the first crystalline phase belonging to the hexagonal system and the P63 / m space group, which is consistent with the peak positions of the CeCl3 pdf card. Furthermore, the first three peaks of the X-ray diffraction pattern of Example 2 are located at 13.802°, 23.886°, and 24.710°, respectively. Example 2 (2-Li-Ce-Al-O-Cl) exhibits a partial second crystalline phase of LiCl, which belongs to the cubic system and the Fm-3m space group.

[0074] The ionic conductivity of Example 2 is as follows Figure 4 As shown, the ionic conductivity was found to be ∼1 mS / cm.

[0075] Application Example 1

[0076] The solid electrolyte (1-Li-La-Al-O-Cl) obtained in Example 1 is in LiIn-LiNi 0.8 Mn 0.1 Co 0.1 Application of O2 (LiIn-NMC811) in all-solid-state batteries. The specific operations are as follows:

[0077] Positive electrode material: Prepare a positive electrode / electrolyte composite material using NMC811 material. Weigh NMC811 and the solid electrolyte (1-Li-La-Al-O-Cl) in Example 1 in a mass ratio of 7:3. Grind them in a glove box for 10 minutes and mix them thoroughly. The resulting mixed powder is used as the positive electrode composite material.

[0078] 80 mg of the solid electrolyte (1-Li-La-Al-O-Cl) from Example 1 was weighed and placed into a 10 mm diameter solid-state battery mold. The mold was pressurized at 100 MPa for 10 seconds to produce a positive-electrode electrolyte disc. Next, 60 mg of Li6PS5Cl electrolyte was added and pressurized at 100 MPa for 20 seconds to produce a negative-electrode electrolyte disc. 10 mg of the positive-electrode composite material was then added to the positive-electrode side. The electrolyte sheet and the positive-electrode material were then integrated under a pressure of 350 MPa. Finally, a LiIn alloy was placed on the negative-electrode side and pressurized at low pressure. All screws on the mold battery housing were tightened to produce a LiIn-NMC811 all-solid-state battery.

[0079] Figure 5 The charge and discharge curve of the LiIn-NMC811 all-solid-state battery at room temperature (25°C) is shown. The all-solid-state battery containing the electrolyte of Example 1 is assembled and charged at a current density of 0.1C until the voltage reaches 3.7V. Then, the all-solid-state battery containing the electrolyte of Example 1 is discharged at the same current density until the voltage reaches 1.9V. The results of the charge and discharge test are shown in Figure 5 In the embodiment 1, the all-solid-state battery of the sample has an initial discharge capacity of 1.1 mAh and a first charge efficiency of 90.09%.

[0080] Application Example 2

[0081] The solid electrolyte (2-Li-Ce-Al-O-Cl) in Example 2 is 0.8 Mn 0.1 Co 0.1 Application of O2 (LiIn-NMC811) in all-solid-state batteries. The specific operations are as follows:

[0082] Positive electrode material: Prepare a positive electrode / electrolyte composite material using NMC811 material. Weigh NMC811 and the solid electrolyte (2-Li-Ce-Al-O-Cl) in Example 2 in a mass ratio of 7:3. Grind them in a glove box for 10 minutes to fully mix the two. The resulting mixed powder is used as the positive electrode composite material.

[0083] 60mg of the solid electrolyte (2-Li-Ce-Al-O-Cl) from Example 2 was weighed and placed into a 10mm diameter solid-state battery mold. The mold was pressurized at 100MPa for 10 seconds to obtain a positive-electrode electrolyte disc. Next, 80mg of Li6PS5Cl electrolyte was added and pressurized at 100MPa for 20 seconds to obtain a negative-electrode electrolyte disc. 10mg of the positive-electrode composite material was then added to the positive-electrode side and the electrolyte sheet and positive-electrode material were integrated under a pressure of 350MPa. Finally, LiIn alloy was placed on the negative-electrode side and pressurized at low pressure. All screws on the mold battery housing were tightened to obtain a LiIn-NMC811 all-solid-state battery.

[0084] Figure 6 The charge and discharge curves of the LiIn-NMC811 all-solid-state battery at room temperature are shown at different discharge rates (0.1C-2C) and voltage settings (1.9V-3.7V). The results demonstrate the excellent electrochemical stability of the all-solid-state battery.

[0085] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oxyhalide electrolyte, characterized in that The Cu Kα ray diffraction image of the oxyhalide electrolyte mainly shows a hexagonal UCl3 structure, and its chemical formula is: Li b M y Al a O3X b+3a+3y-6 ,in: M includes at least one element selected from La, Ce, Pr, Sm, Nd, and U; X includes at least one element selected from F, Cl, Br, and I; 0 <b≤6,0.1≤y≤7,0<a; The oxyhalide electrolyte includes a first crystalline phase, and when tested by X-ray diffraction using Cu Kα rays, a double diffraction peak is present at positions of 2θ=23.6°±0.5° to 2θ=24.7°±0.5°; a single diffraction peak is present at a position of 2θ=13.48°±0.7°; the space group of the first crystalline phase is P63 / m; The oxyhalide electrolyte includes an amorphous phase; The oxyhalide electrolyte includes a second crystal phase and has a diffraction peak at 2θ=30.08°±0.5° in an X-ray diffraction test using Cu Kα rays.

2. The oxyhalide electrolyte according to claim 1, characterized in that 1≤b≤4。 3. A method for preparing an oxyhalide electrolyte, characterized in that: For preparing the oxyhalide electrolyte according to any one of claims 1 to 2; comprising the steps of: Under the protection of an inert atmosphere, metal halide, inorganic lithium salt, aluminum chloride and inorganic metal oxide are mixed and subjected to heat treatment to obtain an oxyhalide electrolyte.

4. The method for preparing an oxyhalide electrolyte according to claim 3, wherein: The heat treatment temperature is 100°C-800°C, and the heat treatment time is 50min-600min.

5. The method for preparing an oxyhalide electrolyte according to claim 4, wherein: When mechanical ball milling is used for mixing, set: The ratio of ball milling beads to raw materials is 2 to 120:1; Ball milling time is 24h~80h; The ball milling speed is 100rpm-600rpm.

6. The method for preparing an oxyhalide electrolyte according to claim 5, wherein: The process also includes a pressing step after the mixing process and before the heat treatment.

7. Use of the oxyhalide electrolyte according to any one of claims 1 to 2 or the electrolyte prepared by the preparation method of the oxyhalide electrolyte according to any one of claims 3 to 6 in the field of batteries.

8. A battery, characterized in that: An electrolyte comprising the oxyhalide electrolyte according to any one of claims 1 to 2 or prepared by the method for preparing the oxyhalide electrolyte according to any one of claims 3 to 6.

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