Al-based oxyhalide solid electrolyte material with high thermal stability

Abstract

The invention discloses an Al-based oxyhalide solid electrolyte material with high thermal stability and a preparation method and application thereof, the Al-based oxyhalide solid electrolyte material is of an amorphous-crystalline phase composite structure and is in a low-modulus phase and high-modulus phase combination, and a component or structure gradient layer exists on a two-phase interface. The chemical general formula of the low-modulus phase is MaAlOcXz (M is Li, Na and other metals, and X is F, Cl and other halogen elements), and the elastic modulus is less than or equal to 20 GPa; the high-modulus phase contains oxides, oxyhalides or halides of La, Zr and other metals, and the elastic modulus is larger than or equal to 30 GPa. The ionic conductivity of the electrolyte at room temperature is greater than 1 mS / cm, the thermal decomposition temperature is greater than 200 DEG C, no obvious thermal effect exists before 150 DEG C, and the interfacial compatibility is good. The preparation process is simple, is suitable for all-solid-state batteries, is beneficial to large-scale production, and provides key guarantee for safe operation of the all-solid-state batteries in a wide temperature range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to an Al-based oxyhalide solid-state electrolyte material with high thermal stability, a preparation method thereof and application thereof in all-solid-state batteries. BACKGROUND

[0002] With the rapid development of renewable energy, the research and development of high-energy-density energy storage devices has become the focus. Although traditional lithium-ion batteries have been commercialized for many years, the flammable safety hazard of organic liquid electrolyte has always existed. In recent years, the frequent occurrence of electric vehicle battery fires has made the demand for energy storage devices with high safety and high energy density more urgent. All-solid-state batteries, with the advantage of all-solid components, can significantly reduce the risk of thermal runaway and still operate stably at extreme temperatures, becoming a research hotspot in the energy storage field. The solid-state electrolyte, as the core of the all-solid-state battery, its characteristics directly affect the performance of the battery. Among them, thermal stability is a key performance indicator of solid-state electrolyte. High-thermal-stability solid-state electrolyte can maintain structural stability and ionic conductivity in a wide temperature range, ensuring the reliable operation of the battery in extreme environments and avoiding thermal-induced performance degradation and safety risks from the root. Compared with liquid electrolytes that are prone to failure at high temperatures, thermal-stable solid-state electrolytes significantly improve battery safety and reduce the risk of thermal runaway. In addition, good thermal stability also helps to extend the cycle life of the battery and improve long-term performance. In the face of the continuous upgrading of energy storage demand, the development of high-thermal-stability solid-state electrolyte is the core direction to promote the breakthrough of all-solid-state battery technology and meet the needs of multiple applications.

[0003] Currently, the inorganic solid-state electrolytes used more include sulfide, halide, and other types of solid-state electrolytes. Sulfide electrolytes (such as Li6PS5Cl) have a relatively high ionic conductivity (up to >10 mS cm -1 ), but their electrochemical window is narrow (~2.6 V vs. Li / Li + ), and they are extremely sensitive to moisture, easily reacting with trace amounts of water in the air to generate toxic H2S gas, which seriously threatens battery safety (Nature Communications, 2022, 13: 7237). Especially, the sulfide solid-state electrolyte and delithiated NCM ternary cathode will chemically react at 100°C, and will cause a fire at 150°C, followed by thermal runaway. In addition, Li7P3S 11 and delithiated lithium cobaltate cathode will produce thermal-chemical reactions at about 300°C, accompanied by an initiation reaction phase and a violent reaction phase (Chem. Mater. 2022, 34, 9159-9171; ACS Nano 2022, 16, 16158-16176). The existence of this thermal runaway risk brings huge safety hazards

[0004] Thus, halide solid-state electrolytes have become a promising up-and-coming material due to their deformability, sinterability, and good (electro)chemical / thermal stability. The trigonal Li3YCl6 prepared by Asano et al. has a Li+ conductivity of 0.51 mS cm-1 at 25 °C -1 and exhibits excellent performance in all-solid-state batteries (Adv. Mater. 2018, 30: 1803075); the Li2ZrCl6 electrolyte developed by Kai Wang et al. has both high ionic conductivity (0.81 mS cm-1 at room temperature -1 ) and compatibility with 4 V-level cathodes (Nature Communications, 2021, 12: 44102). However, halide solid-state electrolytes still face some bottlenecks, such as insufficient ionic conductivity, narrow electrochemical window, insufficient low-modulus phase thermal stability, and poor interface thermal matching, especially the unclear thermal stability of the electrolyte itself and the interface, which to some extent limits their large-scale application and further development. It is worth noting that new types of oxyhalide solid-state electrolytes exhibit excellent electrochemical performance, among which aluminum-based oxyhalide solid-state electrolytes have attracted much attention due to their low cost and high ionic conductivity. More importantly, the present application proposes an aluminum-based oxyhalide solid-state electrolyte with outstanding thermal stability, with a thermal decomposition temperature greater than 200 °C, which is significantly higher than that of most liquid electrolyte materials, and can effectively resist structural degradation and performance decay in high-temperature environments, providing a key guarantee for the safe operation of all-solid-state batteries in a wide temperature range. Its preparation has an expandable strategy, breaking through the limitations of existing technologies, and becoming a core direction for the development of high-performance solid-state electrolytes and the promotion of high-safety all-solid-state batteries.

[0005] In view of the above background, the present application aims to develop a composite structure oxyhalide solid-state electrolyte with high thermal stability, which overcomes the shortcomings of existing solid-state electrolytes in terms of thermal stability, ionic conductivity, etc. through interface gradient design of low-modulus phase and high-modulus phase. SUMMARY

[0006] The technical problem to be solved by the present application is to provide an Al-based oxyhalide solid-state electrolyte material with high thermal stability and a preparation method and application thereof, which has high ionic conductivity and a wide electrochemical window while also having high thermal stability (including electrolyte itself thermal stability and interface thermal stability). The present application provides a new type of oxyhalide electrolyte and a preparation method and application thereof, which has an ionic conductivity of >1 mS cm-1 at room temperature -1 , the components have great adjustability, expanding the oxyhalide electrolyte family, and can be applied in the field of lithium ion batteries, etc., exhibiting good electrochemical performance, and the preparation process is relatively simple, which is conducive to large-scale production.

[0007] The application is realized by the technical scheme as follows:

[0008] An Al-based oxyhalide solid electrolyte material with high thermal stability has an amorphous-crystalline phase composite structure, and the material combination is: low modulus phase @ high modulus phase, wherein:

[0009] The chemical general formula of the low modulus phase is: MaAlOcXz,

[0010] M is one or more elements selected from Li, Na, Ag, Cu, Cs, K, Mg, and Ca;

[0011] X includes one or more elements selected from F, Cl, Br, and I;

[0012] 0.08 < a < 13, 0.1 < c < 6, and 0.5 < z < 8;

[0013] The elastic modulus of the low modulus phase is ≤ 20 GPa; and the amorphous phase is the main phase;

[0014] The composition of the high modulus phase includes one or more of oxides, oxyhalides, and halides containing La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, U, In, Zr, Hf, Ta, Nb, Mo, W, Sc, Y, Ti, V, Ni, Co, Mn, Li metal elements;

[0015] The elastic modulus of the high modulus phase is ≥ 30 GPa;

[0016] There is an interface layer with a composition or structure gradient between the two-phase interface of the low modulus phase @ high modulus phase.

[0017] Preferably, in the low modulus phase @ high modulus phase, the high modulus phase is dispersed in the low modulus phase in the form of particles, microparticles, nanocrystals, etc.

[0018] Preferably, to improve the ionic conductivity and deformability of the lithium-based solid electrolyte, X can be Cl, and the low modulus phase composition formula can be written as MaAlOcXz;

[0019] Preferably, the metal elements corresponding to M can be derived from metal halides such as lithium chloride, sodium chloride, silver chloride, potassium chloride, cesium chloride, magnesium chloride, and calcium chloride;

[0020] Preferably, the metal elements of the high modulus phase can be derived from halides and oxyhalides, such as lanthanum chloride, lanthanum oxychloride, cerium chloride, zirconium chloride, zirconium oxychloride, hafnium chloride, and hafnium oxychloride;

[0021] Preferably, the Al element can be derived from aluminum chloride, aluminum oxychloride, aluminum oxide, lithium aluminate, lithium aluminum chloride, and other Al-containing compounds;

[0022] Preferably, 0.2≤c≤5, at which the ion conductivity of the Al-based oxyhalide solid electrolyte is higher.

[0023] In addition, in the Al-based oxyhalide, the electronegativity of the oxygen element is greater than that of the halogen element (such as Cl), and the introduction of the oxygen element helps to increase the oxidation stability, thereby improving the overall electrochemical window of the electrolyte.

[0024] Preferably, the Al-based oxyhalide has a self-thermal stability of up to 200°C or above, and does not undergo thermal decomposition below 200°C; in addition, the all-inorganic solid-state battery assembled using the high-thermal-stability Al-based oxyhalide solid electrolyte can be stably operated at up to 100°C, and does not have a thermal chemical reaction with the positive electrode material, without the risk of thermal runaway.

[0025] The oxyhalide electrolyte according to the present application can have a certain degree of flexibility, which makes it easier to apply to the assembly process of the all-solid-state battery, facilitates the design of new all-solid-state battery devices, and helps to reduce the pressure required for the current assembly of all-solid-state batteries.

[0026] In terms of appearance, the oxyhalide electrolyte according to the present application is diversified, and common forms include granular, gelatinous, thin film, layered, agglomerated, nanostructured, and porous structures.

[0027] In terms of size, the oxyhalide electrolyte is not limited and can be micron-sized or nanometer-sized, etc.

[0028] In addition, the oxyhalide electrolyte according to the present application exhibits good stability with the positive electrode material and is suitable for use as a positive electrode-side electrolyte. Moreover, it inherits the excellent deformability of the oxyhalide electrolyte and can be closely attached to the positive electrode particles, thereby effectively promoting the rapid interface mass transfer process.

[0029] A preparation method of a high-thermal-stability Al-based oxyhalide electrolyte is used to prepare the above-mentioned electrolyte; comprising the steps of: mixing metal halides, inorganic ionic salts, Al-containing substances (such as aluminum chloride, etc.), and inorganic metal oxides in a certain proportion under an oxygen-free and water-free environment, and obtaining the oxyhalide electrolyte after heating treatment.

[0030] Optionally, the inorganic metal oxide includes antimony-containing oxide;

[0031] The mixing process can adopt one or more combinations of mechanical mixing methods (such as manual grinding, air jet milling, etc.), and mechanical chemical methods (such as low-energy or high-energy ball milling, etc.); preferably, a combination process of grinding and mechanical ball milling is adopted.

[0032] When mechanical ball milling is adopted for mixing, the ball milling parameters are as follows: the mass ratio of ball milling beads to raw materials is 20-100:1; the ball milling time is 0.5 h-60 h; and the ball milling rotation speed is 50 rpm-700 rpm, so as to ensure the uniformity of mixing.

[0033] The process parameters of the heating treatment can be adjusted according to actual needs, and the temperature range is 25°C-800°C, and the time length is 10 min-50 h. The raw materials after mixing are placed in a heating device to complete the heating treatment, and the device can adopt a conventional resistance heating furnace, etc.

[0034] In addition, a pressing forming process can be selectively added between the mixing and the heating treatment. The pre-mixed raw materials can be made into various shapes (such as square, circular, etc.) under a certain pressure, and the appearance and size of the formed materials are not limited. It should be noted that the pressing forming is not a mandatory step, and if this step is adopted, the pressure range is recommended to be in the conventional industrial pressure range (such as 1 MPa-50 MPa).

[0035] Overall, the preparation method of the oxyhalide electrolyte of the present application mainly covers two steps of pre-mixing and heating treatment: first, the raw materials are fully pre-mixed; second, whether to perform pressing forming is selected according to needs; finally, the mixed materials (or the raw materials after forming) are subjected to heating treatment, so as to obtain an oxyhalide solid-state electrolyte with excellent ionic conductivity.

[0036] The present application also relates to the application of the high-thermal-stability Al-based oxyhalide solid-state electrolyte or the electrolyte prepared by the above preparation method in the field of batteries.

[0037] The high-thermal-stability Al-based oxyhalide solid-state electrolyte can be applied to many components of batteries, such as positive electrodes, negative electrodes, electrolytes, interface layers, modification layers, protective layers, etc.; for example, it can also be applied to any component of doped or coated batteries and related links.

[0038] If it is applied to the positive electrode side, it can be used to improve the performance of the positive electrode material, and is suitable for various battery types such as full solid-state batteries and semi-solid-state batteries. When used as an electrolyte, it can be used in full solid-state lithium batteries. Generally, a full solid-state battery mainly consists of a positive electrode active material, a solid-state electrolyte, and a negative electrode material, etc.

[0039] An electrode comprising the high-thermal-stability Al-based oxyhalide solid-state electrolyte.

[0040] Application of a high-thermal-stability Al-based oxyhalide solid-state electrolyte in the field of batteries.

[0041] A battery comprising the high-thermal-stability Al-based oxyhalide solid-state electrolyte described above.

[0042] In the application scenario of all-solid-state lithium batteries, the positive active material covers lithium-containing transition metal oxides commonly used in lithium-ion batteries, such as Li(Ni x CoyAlz) O2, Li(Ni x CoyMnz) O2, and LiCoO2, etc., and also includes transition metal fluorides, polyanion compounds, fluorinated polyanion compounds, transition metal sulfides, transition metal oxysulfides, and transition metal oxynitrides. In addition, these positive electrode materials can also be improved in stability and specific capacity through secondary improvement methods such as coating, doping, and interface engineering. Such materials occupy an important position in the field of lithium-ion battery positive electrodes due to their excellent electrochemical performance.

[0043] To fully exhibit the advantages of all-solid-state batteries, such as electrochemical stability, good charge and discharge performance, and efficient ion transport capacity, in the assembly of solid-state batteries, in addition to the positive active material, negative material, and the electrolyte provided by the present application, other electrolytes can be selected according to the needs; the other electrolyte can be solid or gel.

[0044] From the perspective of safety of all-solid-state lithium batteries, the positive active material can be preferably lithium manganate-based positive material LiNi 0.8 Mn 0.1 Co 0.1 O2(NMC811), and the negative material can be selected from lithium metal, Li-In alloy, silicon negative electrode, or other corresponding negative electrode. As for other electrolytes, solid oxide, sulfide, or halide electrolytes can be selected.

[0045] Compared with the prior art, the oxyhalide solid-state electrolyte of the present application has the following advantages:

[0046] 1. High thermal stability: through the design of amorphous-crystalline phase composite structure and the interface gradient regulation of low-modulus phase and high-modulus phase, the oxyhalide can still maintain stable structure and performance at a higher temperature, with a thermal decomposition temperature greater than 200°C, and no obvious thermal effect before 150°C by differential scanning calorimetry test, effectively avoiding battery safety accidents caused by thermal runaway and other factors, and significantly improving the safety performance and service life of all-solid-state batteries in high-temperature environments.

[0047] 2. Higher ionic conductivity: at room temperature, the ionic conductivity can reach >1 mS・cm -1, which is superior to traditional halide solid-state electrolytes, ensures fast ion transport during charging and discharging of the battery, and improves the rate performance of the battery.

[0048] 3. Good interface compatibility: with the help of the interface gradient layer design, the interface has good thermal stability with the electrode material, reducing the occurrence of interface side reactions, thereby improving the overall performance and cycle stability of the all-solid-state battery.

[0049] 4. Production potential: the components are highly adjustable, the preparation process is simple and controllable, and have application prospects for large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0050] The drawings described herein are used to provide further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0051] Figure 1 High-resolution transmission electron micrograph of the solid-state electrolyte (LAOC-Ce) obtained in Example 1 of the present application.

[0052] Figure 2 Thermal stability diagram of the solid-state electrolyte of Comparative Example 1 of the present application and the solid-state electrolyte (LAOC-Ce) of Example 1 of the present application.

[0053] Figure 3 Full-inorganic solid-state battery charge-discharge cycle of the solid-state electrolyte (LAOC-Ce) obtained in Example 1 of the present application under high temperature (80°C) conditions.

[0054] Figure 4 Full-inorganic solid-state battery charge-discharge cycle of the solid-state electrolyte (LAOC-Sm) obtained in Example 2 of the present application under high temperature (100°C) conditions. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application will be further described in detail below in combination with examples and drawings, the schematic embodiments of the present application and their descriptions are only used to explain the present application, and do not constitute a limitation on the present application.

[0056] Performance test:

[0057] X-ray diffraction test: in a laboratory environment, an X-ray diffractometer is used to determine the sample by Kα rays, the wavelength λ is determined as 1.54056 Å, and the test is carried out in a flat table mode.

[0058] Ionic conductivity test: Ionic conductivity test was performed by means of EC-Lab electrochemical workstation with the method of alternating current impedance. The mold cell used in the test was of a structure of stainless steel / electrolyte material / stainless steel. The specific operation process was as follows: a specific mass (for example, 200 mg) of electrolyte material was accurately weighed in an oxygen-free environment and placed in a mold cell with a diameter of 10 mm. Then, the electrolyte material was cold-pressed into a disc with a diameter of 10 mm by using a pressure of 350 MPa. The area of the electrolyte disc was recorded as S, and the pressure was maintained for 30 seconds. The area (S) and thickness (L) of the disc were measured, and the test was performed at 25°C, and calculated as σ = L / (R x S) (R is the impedance value).

[0059] Thermal stability test: Differential scanning calorimeter (DSC) was used to record whether there was a thermal effect (such as a melting peak or a decomposition peak) before 150°C under an inert atmosphere at a rate of 10°C / min from room temperature to 300°C.

[0060] Elastic modulus test was tested by nanoindentation test, acoustic velocity method or atomic force microscope test.

[0061] Assembly and test of all-solid-state battery: The positive electrode material of the all-solid-state battery was NCM811 (LiNi0.8Mn0.1Co0.1O2) ternary positive electrode material, and the negative electrode was Li-In alloy. On the positive electrode side, the oxygen halide-based electrolyte material selected was the product prepared in the above examples; on the negative electrode side, a conventional sulfide (such as Li6PS5Cl) electrolyte was matched. During the battery assembly process, appropriate pressure was applied to each level of material to ensure interlayer contact.

[0062] The Al-based oxygen halide solid-state electrolyte of the embodiment of the application is an amorphous-crystalline phase composite structure of a low modulus phase and a high modulus phase, and there is a composition or structure gradient layer at the interface of the two phases. The low modulus phase has a chemical formula of MaAlOcXz (M is Li, Na, etc., and X is F, Cl, etc.), and the elastic modulus is ≤20 GPa, mainly in the form of amorphous phase; the high modulus phase contains halides / halogen oxides of metals such as La, Ce, and Sm, and the elastic modulus is ≥30 GPa. The preparation uses a “pre-mixing-heat treatment” process, and the raw materials are commercially available metal halides, aluminum-containing substances, and metal oxides (purity ≥99.9%), without the need for special purification.

[0063] Example 1

[0064] This embodiment provides a new type of oxygen halide electrolyte, and the specific preparation method is as follows:

[0065] S1 raw material ratio: lithium chloride (LiCl), cerium chloride (CeCl3, high modulus phase), aluminum chloride (AlCl3, one of the sources of low modulus phase), antimony oxide (Sb2O3) are weighed according to the mass ratio of 2.5:3.2:1.3:2, and the purity is all ≥99.9%;

[0066] S2 mixing: in an oxygen-free and water-free glove box, the raw materials are ground in an agate mortar for 30 min until uniform;

[0067] S3 heat treatment: transfer to an alumina crucible, heat at 260°C for 4 h under argon atmosphere, and after natural cooling, obtain example 1, recorded as example 1 (LAOC-Ce).

[0068] High-resolution transmission electron microscopy shows that it is an amorphous-crystalline phase composite structure, and high elastic modulus particles, microparticles, nanocrystals, etc. are dispersed in the low modulus phase, as shown in Figure 1 The existence of high modulus phase improves the thermal stability of the overall material, which is due to the synergistic effect and interface regulation effect of the dispersed-matrix phase, and the high modulus phase can effectively inhibit the thermal deformation (such as softening, flowing) and structural relaxation of the low modulus phase at high temperature. The interface gradient layer between the high modulus phase particles and the low modulus phase matrix can reduce the interface stress concentration caused by the difference in thermal expansion coefficient between the two phases, and avoid the structural damage caused by stress tearing at high temperature. The high modulus phase nanocrystals / microparticles act as heterogeneous nucleation points for the low modulus phase (amorphous phase), anchoring the disordered structure of the low modulus phase through the interaction at the interface, and improving its transition temperature.

[0069] The ionic conductivity of the solid-state electrolyte obtained in example 1 is tested, and the ionic conductivity is 1.5 mS / cm.

[0070] Example 2

[0071] This example provides a new type of oxyhalide electrolyte, and the specific preparation method is as shown below:

[0072] S1 raw material ratio: lithium chloride (LiCl), samarium chloride (SmCl3, high modulus phase), aluminum chloride (AlCl3, low modulus phase source), antimony oxide (Sb2O3) are weighed according to the mass ratio of 1.1:2.3:0.8:1.7, and the purity is all ≥99.9%;

[0073] S2 mixing: in an oxygen-free and water-free glove box, after grinding for 40 min, ball milling is carried out at a ball-to-material ratio of 50:1 and a rotation speed of 500 rpm for 2 h;

[0074] S3 heat treatment: transfer to an alumina crucible, heat at 280°C for 3 h under inert atmosphere, and after natural cooling, obtain example 2 solid-state electrolyte material, recorded as example 2 (LAOC-Sm).

[0075] The ion conductivity of the solid-state electrolyte obtained in Example 2 was tested, and the ion conductivity thereof was 0.84 mS / cm.

[0076] Comparative Example 1 (single low modulus phase electrolyte)

[0077] Preparation of Al-based oxyhalide electrolyte without high modulus phase: only lithium chloride, aluminum chloride, and antimony oxide were mixed in a molar ratio of 2.5:1.3:2, and the same heat treatment as in Example 1 was performed at 260°C for the same time.

[0078] The ion conductivity of the solid-state electrolyte obtained in Comparative Example 1 was tested, and the ion conductivity thereof was 0.74 mS / cm.

[0079] Thermal stability tests were performed on Comparative Example 1 and Example 1, as shown in FIG. 2. It can be clearly observed that Comparative Example 1 has a significant endothermic peak near 150°C, representing the thermal effect behavior of the material of Comparative Example 1, which causes the structure to deteriorate, while the endothermic peak at 150°C disappears in Example 1, and the electrolyte material of Example 1 maintains good properties. Figure 2

[0080] Application Example 1

[0081] Application of the solid-state electrolyte (LAOC-Ce) obtained in Example 1 to a full solid-state battery with LiNi 0.8 Mn 0.1 Co 0.1 O2(NMC811) as the positive electrode and lithium-indium alloy as the negative electrode. The specific operation is as follows:

[0082] Positive electrode material: a positive electrode / electrolyte composite material was prepared using NMC811 material, and NMC811 and the solid-state electrolyte (LAOC-Ce) in Example 1 were weighed in a mass ratio of 7:3, ground in a glove box for 30 min, and fully mixed, and the obtained mixed powder was used as the positive electrode composite material.

[0083] 70 mg of the solid-state electrolyte (LAOC-Ce) in Example 1 was weighed into a solid-state battery mold with a diameter of 10 mm, and a positive electrode side electrolyte disc was obtained by pressing at 100 MPa; then, 70 mg of Li6PS5Cl electrolyte was added, and a negative electrode side electrolyte disc was obtained by pressing at 100 MPa; then, 10 mg of the positive electrode composite material was added to the positive electrode side, and the electrolyte disc and the positive electrode material were integrated into one by pressing at 350 MPa. Finally, the lithium-indium alloy was placed on the negative electrode side, and all the screws of the mold battery shell were tightened to obtain an NMC811-LiIn full solid-state battery.

[0084] Figure 3 ​For high-temperature (80 °C) charge-discharge cycling of LiIn-NMC811 full solid-state batteries, a full solid-state battery containing the electrolyte of Example 1 was assembled, and the results showed that in a solid-state battery in which all components are inorganic materials, efficient electrochemical charge-discharge can be carried out at a relatively high temperature.

[0085] Application Example 2

[0086] Application of the solid-state electrolyte (LAOC-Sm) in Example 2 in LiIn-LiNi 0.8 Mn 0.1 Co 0.1 O2 (LiIn-NMC811) full solid-state battery. The specific operation is as follows:

[0087] Positive electrode material: A positive electrode / electrolyte composite material was prepared using NMC811 material, and NMC811 and the solid-state electrolyte (LAOC-Sm) in Example 2 were weighed in a mass ratio of 7:3, ground in a glove box for 30 min, and fully mixed, and the obtained mixed powder was used as a positive electrode composite material.

[0088] 70 mg of the solid-state electrolyte (LAOC-Sm) in Example 2 was weighed and placed in a solid-state battery mold with a diameter of 10 mm, and a positive electrode side electrolyte disc was obtained by pressing at 100 MPa; then, 70 mg of Li6PS5Cl electrolyte was added, and a negative electrode side electrolyte disc was obtained by pressing at 100 MPa; then, 10 mg of the positive electrode composite material was added to the positive electrode side, and the electrolyte disc and the positive electrode material were integrated into one by pressing at 350 MPa. Finally, the lithium-indium alloy was placed on the negative electrode side, and all the screws of the mold battery shell were tightened to obtain an NMC811-LiIn full solid-state battery.

[0089] Figure 4 For 100 °C charge-discharge cycling of LiIn-NMC811 full solid-state batteries, the voltage setting range was 1.9 V-3.7 V under a 2C charge-discharge rate. The results showed that the full solid-state battery has excellent electrochemical stability at high temperature.

[0090] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An Al-based oxyhalide solid-state electrolyte material having high thermal stability, characterized in that, The amorphous-crystalline phase composite structure has a material combination of a low modulus phase and a high modulus phase, wherein the low modulus phase has a general chemical formula of MaAlOcXz, M is one or more elements selected from Li, Na, Ag, Cu, Cs, K, Mg, and Ca; X includes one or more elements selected from F, Cl, Br, and I; 0.08 < a < 13, 0.1 < c < 6, and 0.5 < z < 8; the elastic modulus of the low modulus phase is less than or equal to 20 GPa; the amorphous phase is the main phase; and the high modulus phase includes one or more of oxides, oxyhalides, and halides of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, U, In, Zr, Hf, Ta, Nb, Mo, W, Sc, Y, Ti, V, Ni, Co, Mn, and Li.

2. The oxyhalide solid-state electrolyte material with high thermal stability according to claim 1, characterized in that, An interface layer exists between the two-phase interface of the low modulus phase and the high modulus phase, and the interface layer has a composition or structure gradient.

3. The oxyhalide solid-state electrolyte material with high thermal stability according to claim 1, characterized in that, The low modulus phase can also contain an additive AN, where A is one or more cations of Li+, Na+, K+, Mg2+, Ca2+, Al3+; N is one or more anions of O2-, S2-, CO32-, PO43-, BF4-, CIO4-, PF6-, SiO4 4 -, SO32-, P2O7 4 -, SO42-, a charge balancing factor of A and N.

4. The oxyhalide solid-state electrolyte material with high thermal stability according to claim 1, characterized in that, In the low modulus phase and the high modulus phase, the high modulus phase is dispersed in the low modulus phase in the form of particles, microparticles, or nanocrystals.

5. The oxyhalide solid-state electrolyte material with high thermal stability according to claim 1, characterized in that, In the amorphous-crystalline phase composite structure, the mass fraction of the low modulus phase is 55% to 92%, and the mass fraction of the high modulus phase is 8% to 45%.

6. A method of producing an Al-based oxyhalide solid-state electrolyte with high thermal stability according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: mixing metal halides, inorganic ion salts, aluminum-containing substances, and inorganic metal oxides in a proper ratio under an oxygen-free and water-free environment, and obtaining the oxyhalide electrolyte after heat treatment.

7. The method of claim 6, wherein the method further comprises, The combination process of grinding and mechanical ball milling is used: the raw materials are ground in a mortar for 5 minutes to 60 minutes, and then mechanical ball milling is performed, wherein: The mass ratio of the ball milling beads to the raw materials is 20 to 100:1, the ball milling time is 0.5 hours to 60 hours, and the ball milling speed is 50 rpm to 700 rpm. The temperature range of the heat treatment is 25°C to 800°C, and the time is 10 minutes to 50 hours.

8. Application of the Al-based oxyhalide solid-state electrolyte with high thermal stability according to any one of claims 1 to 5 in the field of batteries.

9. An electrode characterized by, The Al-based oxyhalide solid-state electrolyte according to any one of claims 1 to 5.

10. A battery, characterized by The Al-based oxyhalide solid-state electrolyte according to any one of claims 1 to 5.

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