A chloride oxide solid electrolyte and its preparation method and application

Abstract

The present invention discloses a chloride oxide solid electrolyte and its preparation method and application. The general chemical formula of the chloride oxide solid electrolyte is A x M y O n Cl z The preparation method comprises: grinding, tableting and heat treating a metal A source, a metal M source and an oxygen source according to a target molar ratio to obtain a chloride oxide solid electrolyte A. x M y O n Cl z The heat treatment involves heating to a temperature above the melting point and then maintaining the temperature to volatilize the HCl gas generated during the reaction. Alternatively, a metal A source, a metal M source, and an oxygen source are subjected to high-energy ball milling at a target molar ratio to prepare an oxychloride solid electrolyte; the oxygen source is AlCl3·6H2O. This solid electrolyte exhibits excellent electrochemical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical energy storage, and in particular to a chloride oxide solid electrolyte and a preparation method and application thereof. Background Art

[0002] All-solid-state batteries (ALLS) offer higher theoretical energy density and greater safety, making them one of the most promising energy storage technologies. Solid-state electrolytes, key materials in ALLS batteries, largely determine their performance. However, the low ionic conductivity and limited synthesis methods of ALLS electrolytes present major challenges in the development of ALLS batteries. Over many years of research and exploration, researchers have focused on developing various solid-state electrolytes and synthetic routes that confer high ionic conductivity.

[0003] The most common solid electrolytes currently available are oxides, sulfides, polymers, and halides. Among them, halide solid electrolytes have high room-temperature ionic conductivity, a wider electrochemical stability window, and matching compatibility with oxide cathode materials. Although halide solid electrolytes have made significant progress, chloride oxides represent a new frontier that exhibits many excellent properties, such as ultrahigh ionic conductivity and viscoelasticity. Therefore, it is crucial to elucidate their complex structure-property relationships and develop new and effective synthetic routes.

[0004] Similar to the synthesis of other types of solid electrolytes, solid-phase reaction is the most commonly used method for synthesizing halide solid electrolytes, such as mechanical ball milling, annealing, or a combination of the two. The preparation of oxychloride solid electrolytes requires oxygen doping in the starting materials, which can be achieved by adding an oxygen source, heating, or mechanical milling.

[0005] Disadvantages of existing technology:

[0006] Currently, oxychloride solid electrolytes hold great promise for pushing the limits of battery performance, but their single synthesis method makes large-scale mass production difficult. Furthermore, the raw materials used for their synthesis contain a high proportion of rare earth elements, which is costly. Summary of the Invention

[0007] The present invention provides a chloride oxide solid electrolyte, a preparation method, and an application thereof. The chloride oxide solid electrolyte is low in cost and suitable for large-scale preparation. It also has high room-temperature ionic conductivity, is compatible with high-voltage positive electrode materials, and exhibits excellent rate and cycle stability when assembled into an all-solid-state battery.

[0008] The present invention is achieved through the following technical solutions:

[0009] A method for preparing an oxychloride solid electrolyte comprises the following steps:

[0010] The metal A source, the metal M source and the oxygen source are ground, pressed and heat treated according to the target molar ratio to prepare the chloride oxide solid electrolyte A. x M y O n Cl z The heat treatment is as follows: heating to a temperature higher than the melting temperature and keeping the temperature high to volatilize the HCl gas generated during the reaction;

[0011] Alternatively, the metal A source, the metal M source and the oxygen source are subjected to high-energy ball milling according to the target molar ratio to prepare the chloride oxide solid electrolyte A. x M y O n Cl z ;

[0012] Wherein, A includes Li or Na, and M includes one or more of Al, Ga, In, Zr, Hf, Nb, Ta, Y, La, Ce, Nd, Ge, and Sb; the stoichiometric coefficients satisfy 0.5≤x≤9, 0.5≤y≤9, 1≤n≤6, and 0≤z≤36, and the values of x, y, n, and z satisfy the charge balance of the chemical formula;

[0013] The preparation process is carried out in an inert atmosphere; AlCl3·6H2O is used as the oxygen source.

[0014] The preparation method provided by the present invention has two paths. One path is: the raw materials are prepared by manual grinding, tableting and heat treatment, and a reaction occurs during the heat treatment process; the other path is: the raw materials are subjected to high-energy ball milling, and a reaction occurs during the ball milling process.

[0015] The present invention provides a novel oxychloride solid electrolyte with a multiphase composite structure. The oxychloride solid electrolyte is formed by introducing an oxygen source into a molten salt mixture to replace the halogen element. + Or Na + The polyanion groups at the transport sites achieve faster ion conduction and material modification, thereby realizing excellent rate and cycle stability of all-solid-state batteries.

[0016] The crystal structure of the synthetic raw material AlCl3·6H2O crystalline hydrate (space group P-3c) is as follows Figure 1 As shown, it can be regarded as Al(H2O)6 3+ The aluminum and six water molecules form a tightly packed octahedron with hexagonal close packing of bonded hydrogen units along the c-axis. Each hydrogen atom further connects to a chlorine atom to form an Al-OH···Cl bond. During heating, oxygen is introduced into the final oxychloride solid electrolyte by releasing HCl gas. The reaction principle is as follows:

[0017] a LiCl+b AlCl3+AlCl3·6H2O→6Li a / 6 Al (b+1) / 6 OCl (a+3b-9) / 6 +12HCl↑.

[0018] The chlorine oxide solid electrolyte provided by the present invention can replace the traditional organic liquid electrolyte, thereby improving the safety and energy density of the battery.

[0019] Further optionally, the environment of the preparation process meets the following requirements: inert atmosphere protection, H2O content less than 0.1ppm, and O2 content less than 0.1ppm.

[0020] Further optionally, the grinding time is 5 min to 15 min; and / or the ball milling time is 1 h to 60 h.

[0021] The raw materials are ground and mixed by manual grinding or mechanical ball milling. When manual grinding is used, the grinding time is 5 minutes to 15 minutes; when mechanical ball milling is used, the ball milling time is 1 hour to 60 hours.

[0022] Further optionally, and / or, the pressure applied during tabletting is 200 MPa to 300 MPa; and / or, the heating and melting temperature is 200° C. to 500° C., and the holding time is 2 h to 5 h.

[0023] A chloride oxide solid electrolyte, prepared by the above-mentioned method for preparing a chloride oxide solid electrolyte;

[0024] Further optionally, the solid electrolyte has a nano-sized microcrystalline phase and an amorphous phase, the main microcrystalline phase is a distorted rock salt phase structure similar to LiCl or NaCl, and the nanocrystals are embedded in the amorphous matrix.

[0025] The solid electrolyte provided by the present application has a nano-sized microcrystalline phase and a large amount of amorphous phase components.

[0026] Further optionally, the mass percentage of the amorphous phase component is more than 50%, and the amorphous component contains [M a O b Cl c ] (2b+c-ma)- Polyanionic groups. When manually milled, the mass percentage of the amorphous phase component is 50% to 60%; when high-energy ball milling is used, the mass percentage of the amorphous phase component reaches more than 60%, or even completely amorphous material.

[0027] Different configurations of [M a O b Cl c ] (2b+c-ma)- Polyanionic groups (e.g. Al2O2Cl4 2-,Al2OCl6 2- ,Al3O2Cl6 - ,Al3OCl8 - ,Al4O2Cl 10 2- etc.) have the characteristics of short-range order and long-range disorder, providing Li + Or Na + Transport sites promote Li in oxychloride solid electrolytes + Or Na + transmission, m is the valence of the metal element M.

[0028] The oxychloride solid electrolyte provided by the present invention has the characteristics of simple synthesis, high cost-effectiveness and stable electrochemical performance, and has significant advantages over other solid electrolytes. a O b Cl c ] (2b+c-3a)- The formation of polyanions is the cause of Li + An important factor in the diversification of local environments, Li + Able to transport through O and Cl sites, Li + -[Al a O b Cl c ] (2b+c-3a)- The interaction weakens, ultimately promoting Li + Faster local mobility. In addition, the electrochemical performance test verified its feasibility as a solid electrolyte for all-solid-state batteries.

[0029] The invention discloses an application of a chloride oxide solid electrolyte in the battery field.

[0030] A solid-state battery comprises the electrolyte obtained by the above-mentioned preparation method, or the above-mentioned oxychloride solid electrolyte.

[0031] The present invention has the following advantages and beneficial effects:

[0032] 1. The present invention introduces groups such as water of crystallization or hydroxyl groups into the raw materials, replacing halogen elements with oxygen. HCl gas is produced and released as a byproduct during the reaction, and the reaction proceeds fully in the forward direction. This preparation method is scalable, has low production costs, and can achieve large-scale solid-state electrolyte production.

[0033] 2. The oxychloride solid electrolyte provided by the present invention comprises a crystalline phase and an amorphous phase component, wherein the amorphous component has different configurations of [M a O b Cl c ] (2b+c-ma)- The polyanionic group provides Li + Or Na+ The transport sites have the characteristics of short-range order and long-range disorder, which promotes the Li + Or Na + transmission, m is the valence of the metal element M.

[0034] 3. The ionic conductivity of the oxychloride solid electrolyte material prepared by the present invention at room temperature is in the range of 10 -5 Scm -1 ~10 -2 S cm -1 , preferably 10 -3 S cm -1 ~10 -2 S cm -1 , which makes the solid electrolyte material prepared by the present invention extremely advantageous in the application of high-rate all-solid-state batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 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:

[0036] Figure 1 This is the crystal structure of AlCl3·6H2O, the raw material for synthesis in the embodiment of the present invention.

[0037] Figure 2 The solid electrolyte LiAl prepared in Example 1 of the present invention 1.5 OCl 3.5 XRD crystal diffraction data diagram.

[0038] Figure 3 The solid electrolyte LiAl prepared in Example 1 of the present invention 1.5 OCl 3.5 , compared with commercial single crystal LiNi 0.88 Co 0.09 Mn 0.03 Cycling performance diagram of all-solid-state batteries composed of O2 positive electrode materials.

[0039] Figure 4 The solid electrolyte Li prepared in Example 2 of the present invention 1.5 Al 1.5 XRD crystal diffraction data of OCl4.

[0040] Figure 5 The solid electrolyte Li prepared in Example 2 of the present invention 1.5 Al 1.5 TEM image of OCl4.

[0041] Figure 6 The solid electrolyte Li prepared in Example 2 of the present invention1.5 Al 1.5 Kilogram-scale image of OCl4.

[0042] Figure 7 The solid electrolyte Li prepared in Example 2 of the present invention 1.5 Al 1.5 OCl4, with lithium-rich Li 1.14 Ni 0.29 Mn 0.57 Cycling performance diagram of all-solid-state batteries composed of O2 positive electrode materials.

[0043] Figure 8 The solid electrolyte Li prepared in Example 2 of the present invention 1.5 Al 1.5 OCl4, combined with lithium cobalt oxide LiCoO2 positive electrode material to form an all-solid-state battery cycle performance diagram.

[0044] Figure 9 The solid electrolyte Li prepared in Example 3 of the present invention 1.5 Al2OCl 5.5 XRD crystal diffraction data diagram.

[0045] Figure 10 This is the XRD crystal diffraction data diagram of the solid electrolyte LiAl2OCl5 prepared in Example 3 of the present invention.

[0046] Figure 11 The solid electrolyte Na prepared in Example 4 of the present invention 1.5 Al 1.5 OCl4 and NaAl 1.5 OCl 3.5 Temperature-dependent ionic conductivity diagram.

[0047] Figure 12 The solid electrolyte Li5Ta5AlO6Cl prepared in Example 5 of the present invention 21 、Li5Nb5AlO6Cl 21 、Li9Zr9AlO6Cl 36 、Li9Hf9AlO6Cl 36 XRD crystal diffraction data diagram.

[0048] Figure 13 The solid electrolyte Li5Ta5AlO6Cl prepared in Example 5 of the present invention 21 、Li5Nb5AlO6Cl 21 、Li9Zr9AlO6Cl 36 、Li9Hf9AlO6Cl 36 Temperature-dependent ionic conductivity diagram.

[0049] Figure 14This is the XRD crystal diffraction data diagram of the solid electrolyte NaAlOCl2 prepared in Example 6 of the present invention. DETAILED DESCRIPTION

[0050] 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.

[0051] Example 1

[0052] This embodiment provides a chloride oxide solid electrolyte LiAl 1.5 OCl 3.5 , the specific preparation method is as follows:

[0053] Step 1: LiCl, AlCl3, and AlCl36H2O in a molar ratio of 6:8:1 were manually ground in an agate mortar for 8 min and mixed well.

[0054] Step 2: The mixture was placed in a stainless steel mold with a diameter of 13 mm and tableted under a pressure of 300 MPa.

[0055] Step 3: Then, the pressed product was placed in a quartz glass bottle and heated to 260°C to melt, and kept warm for 3 hours to allow it to fully react. During this reaction, a large amount of HCl volatilized. After the reaction system was naturally cooled to room temperature, LiAl 1.5 OCl 3.5 Chloride oxide solid electrolyte product. All steps and experimental processes were carried out in a glove box filled with argon atmosphere (H2O <1ppm, O2 <1ppm) to prevent the reaction raw materials from absorbing water or reacting with oxygen.

[0056] The reaction principle is as follows:

[0057]

[0058] Performance testing and structural characterization:

[0059] 1. Ionic conductivity: The ionic conductivity of the oxychloride solid electrolyte prepared in this embodiment was measured to be 0.79×10 -3 S cm -1 .

[0060] 2. Structural characterization: LiAl 1.5 OCl 3.5 X-ray diffraction data of solid electrolytes such as Figure 2 As shown, the main crystalline phase is a cubic rock salt structure, and the secondary crystalline phase is the diffraction peak of LiAlCl4.

[0061] The crystal structure of the synthetic raw material AlCl3·6H2O crystalline hydrate (space group P-3c) is as follows Figure 1 As shown, it can be regarded as Al(H2O)6 3+ The hexagonal closest packing of the bonded hydrogen units along the c-axis forms a tightly packed octahedron with aluminum and six water molecules. Each hydrogen atom further connects to a chlorine atom to form an Al-OH···Cl bond. During heating, oxygen is introduced into the final oxychloride solid electrolyte by releasing HCl gas.

[0062] 3. Electrochemical performance: In order to verify the application of this material in all-solid-state batteries, Figure 3 LiAl obtained in Example 1 1.5 OCl 3.5 Solid electrolyte and LiNi 0.88 Co 0.09 Mn 0.03 The all-solid-state lithium-ion battery assembled with O2 (NCM88) positive electrode material and lithium indium negative electrode has a voltage range of 2.5V to 4.3V and a charge and discharge rate of 0.5C (0.8mA cm -2 ) Cycling performance diagram at current density. A thin layer of Li6PS5Cl is used to separate the solid electrolyte and the lithium indium negative electrode to minimize the impact of adverse interfacial reactions. 1.5 OCl 3.5 The NCM88 all-solid-state battery with solid electrolyte showed excellent long-cycle performance at room temperature, maintaining 84.86% of its capacity after 1500 cycles and delivering 138.4 mAh g -1 High discharge capacity.

[0063] Example 2

[0064] This embodiment provides a chloride oxide solid electrolyte Li 1.5 Al 1.5 OCl4, the specific preparation method is as follows:

[0065] Step 1: LiCl, AlCl3, and AlCl3·6H2O in a molar ratio of 9:8:1 were manually ground in an agate mortar for 8 min and mixed well.

[0066] Step 2: The mixture was placed in a stainless steel mold with a diameter of 13 mm and tableted under a pressure of 300 MPa.

[0067] Step 3: Then, the pressed product was placed in a quartz glass bottle and heated to 260°C to melt, and kept warm for 3 hours to allow it to fully react. During the reaction, a large amount of HCl volatilized. After the reaction system was naturally cooled to room temperature, Li 1.5 Al 1.5OCl4 oxychloride solid electrolyte product. All steps and experimental processes were carried out in a glove box filled with argon atmosphere (H2O <1ppm, O2 <1ppm) to prevent the reaction raw materials from absorbing water or reacting with oxygen.

[0068] The reaction principle is as follows:

[0069]

[0070] Performance testing and structural characterization:

[0071] 1. Ionic conductivity: The ionic conductivity of the oxychloride solid electrolyte prepared in this embodiment was measured to be 1.04×10 -3 S cm -1 .

[0072] 2. Structural characterization: Li 1.5 Al 1.5 X-ray diffraction data of OCl4 solid electrolyte are as follows Figure 4 As shown, the main crystalline phase is a LiCl cubic rock salt structure, and the second crystalline phase has a different crystal structure from the main crystalline phase, which is the diffraction peak of LiAlCl4.

[0073] Figure 5 For Li 1.5 Al 1.5 The TEM morphology image of OCl4 solid electrolyte reveals its disordered amorphous structure containing a small amount of nano-sized crystallites, and the lattice fringes are attributed to LiCl and LiAlCl4.

[0074] 1 kg Li prepared by this synthesis method 1.5 Al 1.5 OCl4 oxychloride solid electrolyte Figure 6 shown.

[0075] 3. Electrochemical performance: In order to verify the application of this material in all-solid-state batteries, Figure 7 Li obtained in Example 2 1.5 Al 1.5 OCl4 solid electrolyte and lithium-rich cathode Li 1.14 Ni 0.29 Mn 0.57 O2 and lithium indium negative electrode form an all-solid-state lithium-ion battery with a voltage range of 2.5V to 4.8V and a 0.3C (0.364mA cm -2 ) Cycling performance diagram at current density. The all-solid-state battery with lithium-rich cathode still maintained 198.25 mAh g after 160 cycles. -1 high capacity and 93.86% capacity retention rate.

[0076] Figure 8 Li obtained in Example 2 1.5 Al 1.5 OCl4 solid electrolyte, lithium cobalt oxide positive electrode LiCoO2 and lithium indium negative electrode form an all-solid-state lithium-ion battery. In the voltage range of 2.5V to 4.3V, 0.5C (0.38mA cm -2 ) cycle performance diagram at 100% rate. The initial discharge capacity is 145.85 mAh g -1 , with a Coulombic efficiency of 97.3% and a capacity retention of 86.95% over 300 cycles, indicating that Li 1.5 Al 1.5 OCl4 solid electrolyte has application prospects in all-solid-state batteries.

[0077] Example 3

[0078] This embodiment provides a chloride oxide solid electrolyte Li 1.5 Al2OCl 5.5 and LiAl2OCl5, the specific preparation method is as follows:

[0079] Step 1: LiCl, AlCl3, and AlCl3·6H2O in molar ratios of 9:11:1 and 6:11:1, respectively, were manually ground in an agate mortar for 8 min and mixed well.

[0080] Step 2: The mixture was placed in a stainless steel mold with a diameter of 13 mm and tableted under a pressure of 300 MPa.

[0081] Step 3: Then, the pressed product was placed in a quartz glass bottle and heated to 260°C to melt, and kept warm for 3 hours to allow it to fully react. During this reaction, a large amount of HCl volatilized. After the reaction system was naturally cooled to room temperature, Li 1.5 Al2OCl 5.5 All steps and experimental processes were carried out in a glove box filled with argon atmosphere (H2O < 1 ppm, O2 < 1 ppm) to prevent the reaction materials from absorbing water or reacting with oxygen.

[0082] The reaction principle is as follows:

[0083]

[0084] Performance testing and structural characterization:

[0085] 1. Ionic conductivity: The ionic conductivity of the chlorine oxide solid electrolyte prepared in this embodiment is measured to be 0.16×10 -3 S cm -1 and 0.18×10 -3 S cm-1 .

[0086] 2. Structural characterization: Li 1.5 Al2OCl 5.5 The X-ray diffraction data of LiAl2OCl5 solid electrolyte are as follows Figure 9 and Figure 10 As shown in Figure 3, when the proportion of AlCl3 in the raw material is high, a stronger LiAlCl4 diffraction peak can be observed.

[0087] Example 4

[0088] This embodiment provides a solid electrolyte Na 1.5 Al 1.5 OCl4 and NaAl 1.5 OCl 3.5 , the specific preparation method is as follows:

[0089] Step 1: NaCl, AlCl3, and AlCl3·6H2O in molar ratios of 9:8:1 and 6:8:1, respectively, were manually ground in an agate mortar for 8 min and mixed well.

[0090] Step 2: The mixture was placed in a stainless steel mold with a diameter of 13 mm and tableted under a pressure of 300 MPa.

[0091] Step 3: Then, heat the pressed product to 260℃ to melt and keep it warm for 3 hours to allow it to fully react. During this reaction, a large amount of HCl evaporates. After the reaction system is naturally cooled to room temperature, Na 1.5 Al 1.5 OCl4 and NaAl 1.5 OCl 3.5 Chloride oxide solid electrolyte product. All steps and experimental processes were carried out in a glove box filled with argon atmosphere (H2O <1ppm, O2 <1ppm) to prevent the reaction raw materials from absorbing water or reacting with oxygen.

[0092] The reaction principle is as follows:

[0093]

[0094] Performance testing;

[0095] 1. Ionic conductivity: The ionic conductivity of the chlorine oxide solid electrolyte prepared in this embodiment is measured to be 0.14×10 -3 S cm -1 and 0.16×10 -3 S cm -1 , the temperature-dependent ionic conductivity is as follows Figure 11 shown.

[0096] Example 5

[0097] This embodiment provides a solid electrolyte Li5Ta5AlO6Cl 21 、Li5Nb5AlO6Cl 21 、Li9Zr9AlO6Cl 36 、Li9Hf9AlO6Cl 36 , the specific preparation method is as follows:

[0098] LiCl, TaCl5 or NbCl5 or ZrCl4 or HfCl4, AlCl3·6H2O in molar ratios of 5:5:1, 5:5:1, 9:9:1, and 9:9:1 were weighed in a zirconia ball mill with a ball-to-material ratio of 40:1. The mixture was milled in a planetary ball mill at a speed of 600 rpm for 5 h, 5 h, 60 h, and 60 h, respectively. After the milling, Li5Ta5AlO6Cl was obtained. 21 、Li5Nb5AlO6Cl 21 、Li9Zr9AlO6Cl 36 、Li9Hf9AlO6Cl 36 Solid electrolyte, HCl is produced during ball milling. All operation steps and ball mill transfers are carried out under argon atmosphere to prevent the reaction materials from absorbing water or reacting with oxygen.

[0099] Direct mechanical ball milling can form low-crystallinity, metastable crystalline phases and / or amorphous oxychloride solid electrolytes by appropriate ball milling time and speed. The amorphous content may be dominant, exceeding 60% by weight, or even completely amorphous materials.

[0100] Mechanical ball milling is usually performed at room temperature, but heat is generated during high-energy ball milling. Generally, the structure of the oxychloride solid electrolyte is completely different from the starting materials, which indicates that a chemical reaction occurred between the starting materials rather than just a physical mixture of them.

[0101]

[0102]

[0103] Performance testing and structural characterization:

[0104] 1. Ionic conductivity: The ionic conductivity of the oxychloride solid electrolyte prepared in this embodiment is measured to be 5.03×10 -3 S cm -1 , 0.63×10 -3 S cm -1 , 0.16×10 -3 S cm -1, 0.16×10 -3 S cm -1 , the temperature-dependent ionic conductivity is as follows Figure 12 shown.

[0105] 2. Structural characterization: Li5Ta5AlO6Cl 21 、Li5Nb5AlO6Cl 21 、Li9Zr9AlO6Cl 36 、Li9Hf9AlO6Cl 36 X-ray diffraction data of oxychloride solid electrolytes such as Figure 13 As shown, the XRD pattern shows a broad peak near the diffraction angle of 20°, which is due to the amorphous component in the product. In addition, a small amount of microcrystalline diffraction peaks are identified as Li2ZrCl6, Li2HfCl6 and LiCl.

[0106] Example 6

[0107] This embodiment provides a solid electrolyte NaAlOCl2, and the specific preparation method is as follows:

[0108] NaCl, AlCl₃, and AlCl₃·6H₂O were weighed in a 6:5:1 molar ratio into an ultrahigh-energy ball mill. The milling process was performed at a 40:1 ball-to-material ratio and at a rotational speed of 500 rpm, with alternating forward and reverse rotations, for 10 hours. Ultrahigh-energy ball milling was performed at room temperature. Heat and HCl were generated during the milling process, indicating a chemical reaction between the oxychloride starting materials, rather than a mere physical mixture. Upon completion of the milling, the NaAlOCl₂ solid electrolyte product was obtained. All steps and transfers to the mill were performed under an argon atmosphere to prevent the starting materials from absorbing water or reacting with oxygen.

[0109] The reaction principle is as follows:

[0110]

[0111] Structural characterization: X-ray diffraction data of NaAlOCl2 solid electrolyte are as follows Figure 14 shown.

[0112] 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. A method for preparing a chloride oxide solid electrolyte, characterized in that: The following steps are involved: The metal A source, the metal M source and the oxygen source are ground, pressed and heat treated according to the target molar ratio to prepare the chloride oxide solid electrolyte A. x M y O n Cl z The heat treatment is as follows: heating to a temperature higher than the melting temperature and keeping the temperature high to volatilize the HCl gas generated during the reaction; Alternatively, the metal A source, the metal M source and the oxygen source are subjected to high-energy ball milling according to the target molar ratio to prepare the chloride oxide solid electrolyte A. x M y O n Cl z ; Wherein, A includes Li or Na, and M includes one or more of Al, Ga, In, Zr, Hf, Nb, Ta, Y, La, Ce, Nd, Ge, and Sb; the stoichiometric coefficients satisfy 0.5≤x≤9, 0.5≤y≤9, 1≤n≤6, and 0≤z≤36, and the values of x, y, n, and z satisfy the charge balance of the chemical formula; The preparation process is carried out in an inert atmosphere; AlCl3·6H2O is used as the oxygen source; the solid electrolyte has a nano-sized microcrystalline phase and an amorphous phase, the main microcrystalline phase is a distorted rock salt phase structure similar to LiCl or NaCl, and the nano-microcrystals are embedded in the amorphous matrix; the mass percentage of the amorphous phase component is more than 50%, and the amorphous component contains [M a O b Cl c ] (2b+c-ma)- Polyanionic groups.

2. The method for preparing an oxychloride solid electrolyte according to claim 1, wherein: The environment of the preparation process meets the following requirements: inert atmosphere protection, H2O content less than 0.1 ppm, and O2 content less than 0.1 ppm.

3. The method for preparing an oxychloride solid electrolyte according to claim 1, wherein: The grinding time is 5 min to 15 min, and the ball milling time is 1 h to 60 h.

4. The method for preparing an oxychloride solid electrolyte according to claim 1, wherein: and / or, the pressure applied for tableting is 200 MPa to 300 MPa; And / or, the heating melting temperature is 200°C to 500°C, and the holding time is 2 h to 5 h.

5. A chloride oxide solid electrolyte, characterized in that The solid electrolyte is prepared by the method for preparing an oxychloride solid electrolyte as claimed in any one of claims 1 to 4.

6. Use of the chloride oxide solid electrolyte according to claim 5 in the field of batteries.

7. A solid-state battery, characterized in that: The invention comprises the electrolyte obtained by the preparation method according to any one of claims 1 to 3, or the oxychloride solid electrolyte according to claim 5.

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