Lithium oxide composite solid-state electrolyte, preparation method, and use

Abstract

The present disclosure provides a use of one of oxygen-deficient AlPO4-x, TiP2O7-y, and LiTiOPO4-z in an LATP composite solid-state electrolyte material. The present disclosure specifically uses an oxygen-deficient material for LATP modification, and correspondingly provides an LATP composite solid-state electrolyte material. The lithium oxide solid-state electrolyte provided by the present disclosure, which is capable of conducting both ions and electrons, has the advantages of relatively small particle size, excellent structural chemical stability, good hydrophobicity, and broad applicability. When used in a battery, the solid-state electrolyte can improve the capacities of the positive and negative electrodes, offer improved protection for both electrodes, and improve the charging and discharging capacity and the cycling stability of the battery.

Description

A lithium oxide composite solid electrolyte, preparation method and application

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number 202410258212.3, filed with the Patent Office of China on March 6, 2024, entitled “A lithium oxide composite solid electrolyte, preparation method and application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present disclosure belongs to the technical field of LATP lithium oxide solid electrolyte preparation, and relates to a LATP composite solid electrolyte material and a preparation method and application thereof, and in particular to a lithium oxide composite solid electrolyte, a preparation method and application thereof. Background Art

[0004] New battery technologies are crucial for electric vehicles and smart grids. While lithium-ion batteries hold broad application potential, improvements in their energy density and safety have lagged. From a sustainable development perspective, future research in lithium-ion batteries will primarily focus on improving their energy density and safety. Against this backdrop, a new class of all-solid-state secondary lithium batteries has emerged. These batteries, similar in structure to traditional lithium-ion batteries, consist of a cathode, a solid-state electrolyte, and a lithium metal anode. Compared to traditional lithium-ion batteries, all-solid-state secondary lithium batteries offer the following advantages: high safety and long service life; the potential for high energy density; and the high material and chemical stability of the solid-state electrolytes employed in all-solid-state batteries, ensuring their widespread application. Solid-state electrolytes are key components of all-solid-state lithium batteries, primarily replacing the electrolyte in traditional lithium batteries. They possess excellent ionic conductivity and are non-flammable, non-corrosive, non-volatile, and leak-proof, contributing to the high safety, energy density, power density, and long cycle life of all-solid-state lithium batteries. Therefore, the research on solid-state electrolytes is particularly critical to promoting the development of all-solid-state lithium batteries.

[0005] The solid electrolytes currently under research include oxide solid electrolytes, sulfide solid electrolytes, polymer solid electrolytes, and composite solid electrolytes. Oxide solid electrolytes have shown good application prospects due to their excellent ionic conductivity, strong air stability, and simple preparation process. In semi-solid batteries, the LATP oxide solid electrolyte with a NASICON structure also shows a wide range of applicability. In positive electrode blending or coating, it can enhance the stability, cyclability, and safety of the positive electrode material; in diaphragm coating, the electrolyte can improve the wettability of the diaphragm with the electrolyte, enhance the ionic conductivity of the diaphragm, reduce the amount of electrolyte used, and enhance the safety of the positive and negative electrodes.

[0006] However, in the above applications of semi-solid-state batteries, although LATP has a good safety improvement effect, its function is relatively single, and it has not achieved good technical effects in increasing the capacity of battery materials and reducing the internal resistance of batteries.

[0007] Therefore, how to find a more suitable LATP lithium oxide solid electrolyte to solve the above-mentioned problems of LATP has become one of the focuses of widespread attention of many front-line scientific researchers and R&D companies in the field. Summary of the Invention

[0008] The present disclosure provides AlPO with oxygen defects 4-x 、TiP2O 7-y and LiTiOPO 4-z Application of one of them in LATP composite solid electrolyte material;

[0009] Among them, 0<x<4, 0<y<7, 0<z<4.

[0010] In one embodiment, the application is specifically an application as a coating layer of a LATP composite solid electrolyte material;

[0011] The thickness of the coating layer is 50 to 400 nm;

[0012] The LATP composite solid electrolyte material is specifically a LATP composite solid electrolyte material with an oxygen defect coating layer;

[0013] The LATP composite solid electrolyte material further includes LATP and fluorine-doped LATP arranged in the coating layer.

[0014] In one embodiment, the application includes promoting electron transport and improving the electronic conductivity of LATP composite solid electrolyte;

[0015] The applications include improving the charge and discharge capabilities of batteries using LATP composite solid electrolytes;

[0016] The applications include suppressing HF formation in batteries using LATP composite solid electrolytes.

[0017] The present disclosure provides a LATP composite solid electrolyte material, wherein the LATP composite solid electrolyte has a core-shell structure, comprising a LATP material core and an oxygen defect shell;

[0018] The oxygen defect shell is AlPO 4-x 、TiP2O 7-y or LiTiOPO 4-z ;

[0019] Among them, 0<x<4, 0<y<7, 0<z<4.

[0020] In one embodiment, the LATP material core includes LATP and fluorine-doped LATP;

[0021] The D50 particle size of the LATP material core is 0.2-1.5 μm.

[0022] In one embodiment, the mass ratio of the LATP to the fluorine-doped LATP is 1:(0.5-2);

[0023] The mass ratio of the LATP to the oxygen defect shell is 1:(0.1-0.5);

[0024] In the fluorine-doped LATP, the doping mass content of fluorine is 0.25‰ to 3.6‰.

[0025] The present disclosure provides a method for preparing a LATP composite solid electrolyte material, comprising the following steps:

[0026] 1) mixing a first lithium source, a first aluminum source, a first titanium source, and a first phosphorus source to obtain a LATP precursor, and then performing a first sintering to obtain a mixture containing LATP;

[0027] 2) grinding and mixing the mixture containing LATP obtained in the above step and the fluorine-containing grain growth inhibitor, and then sintering for a second time to obtain a composite of LATP and fluorine-doped LATP;

[0028] 3) Grinding and mixing two or more of the second lithium source, the second aluminum source, the second titanium source, and the second phosphorus source with the LATP and fluorine-doped LATP complex obtained in the above step again, and then sintering for a third time under a protective atmosphere to obtain a LATP composite solid electrolyte material with an in-situ oxygen defect coating layer.

[0029] In one embodiment, the first lithium source and the second lithium source each independently include one or more of lithium carbonate, lithium hydroxide and lithium dihydrogen phosphate;

[0030] The first aluminum source and the second aluminum source each independently include one or more of aluminum oxide, aluminum carbonate and aluminum hydroxide;

[0031] The first titanium source and the second titanium source each independently comprise titanium dioxide and / or titanium hydroxide;

[0032] The first phosphorus source and the second phosphorus source independently include one or more of ammonium dihydrogen phosphate, diammonium hydrogen phosphate, titanium pyrophosphate and phosphorus pentoxide.

[0033] In one embodiment, in step 1), the mixing method includes ball milling;

[0034] The mixing time is 3 to 15 hours;

[0035] The mixing speed is 200-500 r / min;

[0036] The chemical formula of the LATP is Li 1+x Al x Ti 2-x (PO4)3, where 0.3≤x≤0.6.

[0037] In one embodiment, the temperature of the first sintering is 450-700°C;

[0038] The heating rate of the first sintering is 1-6°C / min;

[0039] The holding time of the first sintering is 30 to 360 minutes;

[0040] The LATP-containing mixture includes LATP, remaining raw materials and transition products.

[0041] In one embodiment, the fluorine-containing grain growth inhibitor includes one or more of calcium fluoride, aluminum fluoride, and titanium tetrafluoride;

[0042] The mass ratio of the grain growth inhibitor to the mixture containing LATP (0.01-0.1): 1;

[0043] In the step 2), the rotation speed of the grinding and mixing is 200 to 2000 r / min;

[0044] The grinding and mixing time is 1 to 12 hours.

[0045] In one embodiment, the temperature of the second sintering is 450-700°C;

[0046] The heating rate of the second sintering is 1-6°C / min;

[0047] The holding time of the second sintering is 20 to 300 minutes.

[0048] In one embodiment, in step 3), the rotation speed of the re-grinding and mixing is 200 to 500 r / min;

[0049] The grinding and mixing time is 3 to 15 hours;

[0050] The temperature of the third sintering is 400-700°C;

[0051] The heating rate of the third sintering is 0.5-4°C / min;

[0052] The holding time of the third sintering is 5 to 200 minutes.

[0053] The present disclosure also provides the application of the LATP composite solid electrolyte material in any of the above technical solutions, the LATP composite solid electrolyte material in any of the above technical solutions, or the LATP composite solid electrolyte material prepared by the preparation method of any of the above technical solutions in a solid-state battery.

[0054] In one embodiment, the solid battery comprises an all-solid-state lithium battery;

[0055] The application is application in a solid-state battery positive electrode;

[0056] The application in the positive electrode of a solid-state battery is specifically the application as a mixed ion conductor in the positive electrode;

[0057] The application methods include coating and / or blending. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only represent the embodiments of the present disclosure by way of example, and the dimensional ratios in the drawings do not directly correspond to the actual ratios of the embodiments. At the same time, the following drawings only show certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope.

[0059] FIG1 is an XRD phase spectrum of the third component oxygen defect coating layer prepared in an embodiment of the present disclosure;

[0060] FIG2 is a diagram of the first charge and discharge cycle of a battery after the LATP composite solid electrolyte prepared in Example 1 of the present disclosure is mixed with the positive electrode. DETAILED DESCRIPTION

[0061] The advantages of the embodiments in the application content will be explained in the embodiment section of the specification below, and some of them are obvious from the specification, or can be obtained through some embodiments of the embodiments of the present disclosure.

[0062] The technical solution of the present disclosure will be further described below with reference to the accompanying drawings and through some implementation methods.

[0063] In order to make the purpose, technical solutions and advantages of the present disclosure more clear, the present disclosure is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the embodiments described herein are only used to explain the present disclosure and are not intended to limit the present disclosure. In addition, the technical features involved in the various embodiments of the present disclosure described below can be combined with each other as long as they do not conflict with each other. Without departing from the principles of the embodiments of the present disclosure, several improvements and modifications can be made, and these improvements and modifications are also considered to be within the scope of protection of the embodiments of the present disclosure.

[0064] The present disclosure provides AlPO with oxygen defects 4-x 、TiP2O 7-y or LiTiOPO 4-z Application in LATP composite solid electrolyte materials;

[0065] Among them, 0<x<4, 0<y<7, 0<z<4.

[0066] The present disclosure provides AlPO with oxygen defects 4-x 、TiP2O 7-y or LiTiOPO 4-z Compared with the prior art, the present invention uses AlPO with oxygen defects based on conventional LATP materials. 4-x 、TiP2O 7-y or LiTiOPO 4-z It is used in LATP modification, and combined with specific structure and composition, the LATP material is modified to obtain a lithium oxide, which achieves better comprehensive technical effects in battery applications.

[0067] In the present disclosure, 0<x<4, 0<y<7, 0<z<4, may be 0.8<x<3.2, 1<y<6, 0.8<z<3.2, may be 1.6<x<2.4, 1<y<6, 1.6<z<2.4.

[0068] In the present disclosure, the application is specifically an application as a coating layer of a LATP composite solid electrolyte material.

[0069] In the present disclosure, the coating layer has a thickness of 50 to 400 nm, for example, 120 to 330 nm, for example, 190 to 260 nm.

[0070] In the present disclosure, the LATP composite solid electrolyte material is specifically a LATP composite solid electrolyte material having an oxygen defect coating layer.

[0071] In the present disclosure, the LATP composite solid electrolyte material further includes LATP and fluorine-doped LATP disposed in the coating layer.

[0072] In the present disclosure, the applications include promoting electron transport and improving the electronic conductivity of LATP composite solid electrolyte.

[0073] In the present disclosure, the applications include improving the charge and discharge capabilities of batteries using LATP composite solid electrolytes.

[0074] In the present disclosure, the applications include applications in suppressing HF formation in batteries using LATP composite solid electrolytes.

[0075] The present disclosure provides a LATP composite solid electrolyte material, wherein the LATP composite solid electrolyte has a core-shell structure, comprising a LATP material core and an oxygen defect shell;

[0076] The oxygen defect shell is AlPO 4-x 、TiP2O 7-y or LiTiOPO 4-z ;

[0077] Among them, 0<x<4, 0<y<7, 0<z<4.

[0078] In the present disclosure, 0<x<4, 0<y<7, 0<z<4, may be 0.8<x<3.2, 1<y<6, 0.8<z<3.2, may be 1.6<x<2.4, 1<y<6, 1.6<z<2.4.

[0079] In the present disclosure, the LATP material core includes LATP and fluorine-doped LATP.

[0080] In the present disclosure, the D50 particle size of the LATP material core is 0.2-1.5 μm, for example, 0.4-1.1 μm, for example, 0.6-0.9 μm.

[0081] In the present disclosure, the mass ratio of the LATP to the fluorine-doped LATP is 1:(0.5-2), for example, 1:(0.8-1.7), for example, 1:(1.1-1.4).

[0082] In the present disclosure, the mass ratio of the LATP to the oxygen defect shell is 1:(0.1-0.5), for example, 1:(0.18-0.42), for example, 1:(0.26-0.34).

[0083] In the present disclosure, in the fluorine-doped LATP, the doping mass content of fluorine is 0.25‰ to 3.6‰, or 0.5‰ to 3.0‰, or 1.0‰ to 2.5‰, or 1.5‰ to 2.0‰.

[0084] The LATP composite solid electrolyte material provided by the present disclosure is a lithium oxide solid electrolyte capable of simultaneously conducting ions and electrons, namely, a mixed ion conductor lithium oxide. Its core material is the LATP solid electrolyte, which has excellent ionic conductivity and a stable structure. At the same time, the second component in the present disclosure is F-doped LATP, which reduces the binding ability of LATP with water molecules and improves the hydrophobicity of the overall electrolyte material. F doping can also improve the chemical structure stability of the electrolyte, further enhancing the coating ability of the mixed ion conductor lithium oxide solid electrolyte prepared by the present disclosure on the positive electrode. Moreover, the solid electrolyte surface of the present disclosure has an oxygen-deficient third component. The oxygen-deficient structure can promote the transmission of electrons and synergistically improve the charge and discharge capacity of the battery with the small-particle LATP. In addition, the oxygen-deficient third component is generally positively charged and can attract F generated by the decomposition of the combined electrolyte. - , inhibiting the formation of HF, thereby preventing the positive electrode active material from being corroded by HF. The main material of the third component is AlPO 4-x (0<x<4), TiP2O 7-y (0<y<7) or LiTiOPO 4-z (0<z<4), the synergistic effect of the third component and the first and second components can play a better protective effect in the positive electrode coating, isolate the reaction of the positive electrode material with CO2 or H2O, and avoid the production of Li2CO3 or LiOH by-products; the third component also exhibits a certain capacity, thereby to a certain extent playing a role in improving the capacity of the positive electrode sheet or the negative electrode sheet.

[0085] The present disclosure provides a method for preparing a LATP composite solid electrolyte material, comprising the following steps:

[0086] 1) mixing a first lithium source, a first aluminum source, a first titanium source, and a first phosphorus source to obtain a LATP precursor, and then performing a first sintering to obtain a mixture containing LATP;

[0087] 2) grinding and mixing the mixture containing LATP obtained in the above step and the fluorine-containing grain growth inhibitor, and then sintering for a second time to obtain a composite of LATP and fluorine-doped LATP;

[0088] 3) Grinding and mixing two or more of the second lithium source, the second aluminum source, the second titanium source, and the second phosphorus source with the LATP and fluorine-doped LATP complex obtained in the above step again, and then sintering for a third time under a protective atmosphere to obtain a LATP composite solid electrolyte material with an in-situ oxygen defect coating layer.

[0089] The present invention first mixes raw materials of a first lithium source, a first aluminum source, a first titanium source and a first phosphorus source to obtain a LATP precursor, and then performs a first sintering to obtain a mixture containing LATP.

[0090] In the present disclosure, the first lithium source and the second lithium source each independently include one or more of lithium carbonate, lithium hydroxide and lithium dihydrogen phosphate, for example, lithium carbonate, lithium hydroxide or lithium dihydrogen phosphate.

[0091] In the present disclosure, the first aluminum source and the second aluminum source each independently include one or more of aluminum oxide, aluminum carbonate and aluminum hydroxide, for example, aluminum oxide, aluminum carbonate or aluminum hydroxide.

[0092] In the present disclosure, the first titanium source and the second titanium source each independently include titanium dioxide and / or titanium hydroxide, for example, titanium dioxide or titanium hydroxide.

[0093] In the present disclosure, the first phosphorus source and the second phosphorus source each independently include one or more of ammonium dihydrogen phosphate, diammonium hydrogen phosphate, titanium pyrophosphate and phosphorus pentoxide, for example, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, titanium pyrophosphate or phosphorus pentoxide.

[0094] In the present disclosure, in step 1), the mixing method includes ball milling.

[0095] In the present disclosure, the mixing time is 3 to 15 hours, such as 5 to 13 hours, such as 7 to 11 hours.

[0096] In the present disclosure, the mixing rotation speed is 200-500 r / min, for example, 250-450 r / min, for example, 300-400 r / min.

[0097] In the present disclosure, the chemical formula of the LATP is Li 1+x Al x Ti 2-x (PO4)3, wherein 0.3≤x≤0.6, for example, 0.35≤x≤0.55, for example, 0.4≤x≤0.5, for example, 0.42≤x≤0.47.

[0098] In the present disclosure, the temperature of the first sintering is 450-700°C, for example, 500-650°C, for example, 550-600°C.

[0099] In the present disclosure, the heating rate of the first sintering is 1-6° C. / min, for example, 2-5° C. / min, for example, 3-4° C. / min.

[0100] In the present disclosure, the holding time of the first sintering is 30 to 360 minutes, such as 80 to 310 minutes, such as 130 to 260 minutes, such as 180 to 210 minutes.

[0101] In the present disclosure, the LATP-containing mixture includes LATP, remaining raw materials, and transition products.

[0102] The present disclosure then grinds and mixes the mixture containing LATP obtained in the above steps with a fluorine-containing grain growth inhibitor, and then sintering the mixture for the second time to obtain a composite of LATP and fluorine-doped LATP.

[0103] In the present disclosure, the fluorine-containing grain growth inhibitor includes one or more of calcium fluoride, aluminum fluoride and titanium tetrafluoride, for example, calcium fluoride, aluminum fluoride or titanium tetrafluoride.

[0104] In the present disclosure, the mass ratio of the grain growth inhibitor to the mixture containing LATP is (0.01-0.1):1, for example, (0.03-0.08):1, for example, (0.05-0.06):1.

[0105] In the present disclosure, in step 2), the rotation speed of the grinding and mixing is 200 to 2000 r / min, such as 600 to 1600 r / min, such as 1000 to 1200 r / min.

[0106] In the present disclosure, the grinding and mixing time is 1 to 12 hours, such as 3 to 10 hours, such as 5 to 8 hours.

[0107] In the present disclosure, the temperature of the second sintering is 450-700°C, for example, 500-650°C, for example, 550-600°C.

[0108] In the present disclosure, the heating rate of the second sintering is 1-6° C. / min, for example, 2-5° C. / min, for example, 3-4° C. / min.

[0109] In the present disclosure, the holding time of the second sintering is 30 to 360 min, such as 80 to 310 min, such as 130 to 260 min, such as 180 to 210 min.

[0110] Finally, the present invention grinds and mixes two or more of the second lithium source, the second aluminum source, the second titanium source, and the second phosphorus source with the LATP and fluorine-doped LATP complex obtained in the above steps again, and then performs a third sintering under a protective atmosphere to obtain a LATP composite solid electrolyte material with an in-situ oxygen defect coating layer.

[0111] In the present disclosure, in step 3), the rotation speed of the re-grinding and mixing is 200-500 r / min, such as 250-450 r / min, such as 300-400 r / min.

[0112] In the present disclosure, the grinding and mixing time is 3 to 15 hours, such as 5 to 13 hours, such as 7 to 11 hours.

[0113] In the present disclosure, the temperature of the third sintering is 400-700°C, for example, 450-650°C, for example, 500-600°C.

[0114] In the present disclosure, the heating rate of the third sintering is 0.5-4°C / min, such as 1-3.5°C / min, such as 1.5-3°C / min, such as 2-2.5°C / min.

[0115] In the present disclosure, the holding time of the third sintering is 5 to 200 minutes, such as 40 to 160 minutes, such as 80 to 120 minutes.

[0116] The present disclosure provides a lithium oxide solid electrolyte and a preparation method thereof. The present disclosure is based on conventional LATP materials. The present disclosure optimizes and improves the material structure and preparation process, and modifies the LATP material to obtain a lithium oxide, achieving a good comprehensive technical effect in battery applications. The LATP lithium oxide prepared by the present disclosure is prepared by multi-step low-temperature sintering. In the first step of sintering, a first component LATP and an intermediate product or an unreacted raw material are obtained. The first component and the intermediate product or the unreacted raw material are crushed and a grain growth inhibitor is added to perform a second step of sintering. The grain growth inhibitor can inhibit the growth of the grains of the first component to a certain extent during the second step of sintering. In the later stage of sintering, the grain growth inhibitor will be mixed and doped with the original product. The grain growth inhibitor contains fluorine element, which can participate in the reaction in the later stage of sintering to form a second component containing fluorine-doped LATP. Fluorine doping can overall reduce the surface free energy of the second component, reduce the binding ability of the second component with water molecules, and exhibit a certain hydrophobicity. Therefore, after the first two steps of sintering, the first component LATP and the second component fluorine-doped LATP have small grain size, uniform particle size, and the second component exhibits a certain hydrophobicity.

[0117] The present invention adds two or more of lithium source, aluminum source, titanium source and phosphorus source to the first component prepared by the first two steps of sintering and the LATP of the second component, and coats the LATP on the surfaces of the first component and the second component. Then, the third step of sintering is performed under an inert atmosphere to form a third component AlPO with oxygen defects in situ on the surfaces of the first component and the second component. 4-x (0<x<4), TiP2O 7-y (0<y<7) or LiTiOPO 4-z (0<z<4), the third component has oxygen defects and behaves as a positively charged material, thus having excellent electronic conductivity. Thus, the three-component lithium oxide solid electrolyte prepared in the present disclosure can be used as a mixed ion conductor in positive electrode coating or blending applications, avoiding the poor electronic conductivity of traditional solid electrolytes in positive electrode applications. In addition, since the three-component lithium oxide solid electrolyte prepared in the present disclosure behaves as a positive charge as a whole, it will attract F in the electrolyte in battery applications. - , inhibiting the formation of HF and preventing the positive electrode from being corroded by HF; in addition, the synergistic effect of the third component and the first and second components can play a better protective effect in the positive electrode coating, isolating the reaction between the positive electrode material and CO2 or H2O, and avoiding the production of Li2CO3 or LiOH by-products.

[0118] The present disclosure is a complete and detailed overall technical solution that better ensures the structure and properties of the LATP composite solid electrolyte material, further improves its structural chemical stability, hydrophobicity, and versatility, and thereby enhances the charge-discharge capacity and cycle stability of the battery during application. The above-mentioned lithium oxide composite solid electrolyte, preparation method, and application may specifically include the following contents:

[0119] 1. Material preparation

[0120] Lithium source, aluminum source, titanium source and phosphorus source are weighed according to the composition ratio, and ball milled and mixed by planetary ball milling to obtain LATP precursor. The precursor is sintered at low temperature to obtain the first component LATP. The chemical formula of LATP is Li 1+x Al x Ti 2-x (PO4)3(0.3≤x≤0.6).

[0121] Specifically, lithium sources include lithium carbonate, lithium hydroxide, and lithium dihydrogen phosphate.

[0122] Specifically, the aluminum source includes aluminum oxide, aluminum carbonate, and aluminum hydroxide.

[0123] Specifically, titanium sources include titanium dioxide and titanium hydroxide.

[0124] Specifically, the phosphorus source includes: ammonium dihydrogen phosphate, diammonium hydrogen phosphate, titanium pyrophosphate, and phosphorus pentoxide.

[0125] Specifically, the ball milling is performed for 3 to 15 hours at a ball milling speed of 200 to 500 r / min.

[0126] Specifically, the ball milling medium is: anhydrous ethanol and deionized water.

[0127] Specifically, the sintering temperature is 450-700° C., the heating rate is 1-6° C. / min, and the holding time is 30-360 min.

[0128] 2. The first component LATP that was not completely sintered in the first step, the remaining raw materials, and the second product are crushed and sand-milled. A fluorine-containing grain growth inhibitor is added during the sand-milling process. Finally, the sand-milled slurry is dried and then sintered in the second step to obtain the first component LATP and the second component fluorine-doped LATP.

[0129] Specifically, the selected grinding media are deionized water and anhydrous ethanol.

[0130] Specifically, the selected grinding speed is 200-2000 r / min, and the grinding time is 1-12 h.

[0131] Specifically, the ratio of the selected electrolyte powder to the grinding medium is 1:3-10.

[0132] Specifically, the selected blast drying temperature is 80-200° C., and the drying time is 2-24 hours.

[0133] Specifically, the grain growth inhibitor is calcium fluoride, aluminum fluoride, or titanium tetrafluoride.

[0134] Specifically, the mass ratio of the grain growth inhibitor to the primary sintering product is (0.0.1-0.1):1.

[0135] Specifically, the sintering temperature is 450-700° C., the heating rate is 1-6° C. / min, and the holding time is 20-300 min.

[0136] 3. The first component LATP and the second component fluorine-doped LATP obtained by the two-step sintering are ground and crushed, and then mixed with two or more of a lithium source, an aluminum source, a titanium source, and a phosphorus source by a planetary ball mill. The mixed components are dried and sintered in a tubular furnace under an inert atmosphere to obtain a solid electrolyte material of LATP with an in-situ oxygen defect coating layer.

[0137] Specifically, the ball milling is performed for 3 to 15 hours at a ball milling speed of 200 to 500 r / min.

[0138] Specifically, the ball milling media include anhydrous ethanol and deionized water.

[0139] Specifically, the ratio of the ball milling medium to the powder is 1:3-5.

[0140] Specifically, the inert atmosphere is nitrogen or argon.

[0141] Specifically, the sintering temperature is 400-700° C., the heating rate is 0.5-4° C. / min, and the holding time is 5-200 min.

[0142] Specifically, the D50 particle size of the LATP obtained from the first component and the second component is 0.2 to 1.5 μm, and the oxygen defect coating layer of the third component is 50 to 400 nm.

[0143] Specifically, the mass ratio of the first component LATP, the second component fluorine-doped LATP, and the third component oxygen defect coating layer is 1: (0.5-2): (0.1-0.5).

[0144] The present disclosure provides the application of the LATP composite solid electrolyte material in any of the above technical solutions, the LATP composite solid electrolyte material in any of the above technical solutions, or the LATP composite solid electrolyte material prepared by the preparation method of any of the above technical solutions in a solid-state battery.

[0145] In the present disclosure, the solid battery includes an all-solid-state lithium battery.

[0146] In the present disclosure, the application is application in a solid-state battery positive electrode.

[0147] In the present disclosure, the application in the positive electrode of a solid-state battery is specifically the application as a mixed ion conductor in the positive electrode.

[0148] In the present disclosure, the manner of applying includes coating and / or blending, such as coating or blending.

[0149] The above disclosure provides a lithium oxide composite solid electrolyte, preparation method and application. 4-x 、TiP2O 7-y or LiTiOPO 4-zIt is used in LATP modification, and combined with a specific structure and composition, the LATP material is modified to obtain a lithium oxide, which achieves a good comprehensive technical effect in battery applications. The LATP composite solid electrolyte material provided by the present disclosure is a lithium oxide solid electrolyte (mixed ion conductor lithium oxide) that can simultaneously conduct ions and electrons. Its core material is LATP solid electrolyte, which has excellent ionic conductivity and stable structure; at the same time, the second component in the present disclosure is F-doped LATP, which reduces the binding ability of LATP with water molecules and improves the hydrophobicity of the overall electrolyte material, and F doping can improve the chemical structure stability of the electrolyte, further enhancing the coating ability of the mixed ion conductor lithium oxide solid electrolyte prepared by the present disclosure on the positive electrode; and the solid electrolyte surface in the present disclosure has an oxygen-deficient third component, the oxygen-deficient structure can promote the transmission of electrons, and synergistically improve the charge and discharge capacity of the battery with the small-particle LATP. In addition, the oxygen-deficient third component is generally positively charged and can attract F generated by the decomposition of the combined electrolyte. - , inhibiting the formation of HF, thereby preventing the positive electrode active material from being corroded by HF. The main material of the third component is AlPO 4-x (0<x<4), TiP2O 7-y (0<y<7) or LiTiOPO 4-z (0<z<4), the synergistic effect of the third component and the first and second components can play a better protective effect in the positive electrode coating, isolate the reaction of the positive electrode material with CO2 or H2O, and avoid the production of Li2CO3 or LiOH by-products; the third component also exhibits a certain capacity, thereby to a certain extent playing a role in improving the capacity of the positive electrode sheet or the negative electrode sheet.

[0150] The present disclosure also provides a method for preparing a LATP composite solid electrolyte material. This solid electrolyte material undergoes multi-step sintering to produce a small, uniform particle size. This material can fully fill gaps in positive electrode applications of battery materials, accelerate the transfer of lithium ions in the positive electrode, and enhance the battery's charge and discharge capacity. Furthermore, by controlling the preparation process, the contents of the three components and the oxygen defect content can be effectively controlled, allowing for different adjustments for different applications, enabling a single solid electrolyte to meet multiple applications. The preparation method is simple and easy to implement, operates under mild conditions, is highly controllable, and exhibits excellent stability, making it more amenable to industrial production and application.

[0151] The lithium oxide solid electrolyte provided by the present disclosure, which can conduct both ions and electrons simultaneously, has a small particle size, excellent structural chemical stability, good hydrophobicity, and multiple applications. In battery applications, it can increase the capacity of positive and negative electrodes, provide better protection for the positive and negative electrodes, and improve the battery's charge and discharge capabilities and cycle stability.

[0152] The following are typical but non-limiting embodiments of the present disclosure:

[0153] Example 1

[0154] 1. Weigh 10.15g lithium carbonate, 63.22g ammonium dihydrogen phosphate, 21.95g titanium dioxide, 4.67g aluminum oxide, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 3h and the ball milling speed is 500r / min. The slurry after ball milling is kept at 80℃ for 24h and dried. Then sinter once. The sintering temperature is 700℃, the holding time is 30min, and the heating rate is 6℃ / min. After the holding is completed and cooled, the first component of Li 1.5 Al 0.5 Ti 1.5 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 46.50g.

[0155] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 210 g of anhydrous ethanol, the grinding speed was 2000 r / min, and the grinding time was 12 h. 0.23 g of grain growth inhibitor CaF2 was added after grinding for 11 h. The sand-milled slurry was kept warm at 200 ° C in a blast drying oven for 2 h and dried. The dried powder was subjected to a secondary sintering at a sintering temperature of 450 ° C, a holding time of 300 min, and a heating rate of 1 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 69.74 g, and the mass ratio of the first component to the second component was approximately 1:0.5.

[0156] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, then add 1.39g of alumina and 4.39g of ammonium dihydrogen phosphate and mix them using a planetary ball mill. The ball milling medium used is 210g of anhydrous ethanol, the ball milling speed is 200r / min, and the ball milling time is 15h. The slurry after ball milling is dried in a blast drying oven at 80℃ for 12h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 10ml / min, the sintering temperature is 400℃, the holding time is 200min, and the heating rate is 4℃ / min. After the holding is completed, a third component AlPO is obtained. 4-x The first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer are LATP, wherein the D50 particle size of the first and second components LATP is 200nm, the coating layer of the third component is 50nm, and the mass ratio of the first component, the second component and the third component is 1:0.5:0.1.

[0157] Example 2

[0158] 1. Weigh 6.47g lithium hydroxide, 58.25g ammonium dihydrogen phosphate, 27.38g titanium hydroxide, 7.90g aluminum hydroxide, then add 200g deionized water as a ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 15h and the ball milling speed is 200r / min. The slurry after ball milling is kept at 120℃ for 12h and dried. Then, it is sintered once. The sintering temperature is 450℃, the holding time is 360min, and the heating rate is 1℃ / min. After the holding is completed and cooled, the first component of Li 1.6 Al 0.6 Ti 1.4 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 21.34g.

[0159] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 640 g of deionized water, the grinding speed was 200 r / min, and the grinding time was 10 h. 4.26 g of grain growth inhibitor AlF3 was added after grinding for 9 h. The sand-milled slurry was kept at 180 ° C in a blast drying oven for 3 h and dried. The dried powder was subjected to a secondary sintering at a sintering temperature of 700 ° C, a holding time of 20 min, and a heating rate of 6 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 64.01 g, and the mass ratio of the first component to the second component was approximately 1:2.

[0160] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, then add 4.46g of alumina and 10.06g of ammonium dihydrogen phosphate and mix them using a planetary ball mill. The ball milling medium used is 390g of anhydrous ethanol, the ball milling speed is 500r / min, and the ball milling time is 3h. The slurry after ball milling is dried in a blast drying oven at 90℃ for 10h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 150ml / min, the sintering temperature is 500℃, the holding time is 50min, and the heating rate is 1℃ / min. After the holding is completed, a third component AlPO is obtained. 4-x The first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer, wherein the D50 particle size of the first and second components LATP is 1.5 μm, the coating layer of the third component is 400 nm, and the mass ratio of the first component, the second component and the third component is 1:0.5:0.1.

[0161] Example 3

[0162] 1. Weigh 8.96g lithium carbonate, 89.60g titanium pyrophosphate, 1.93g titanium dioxide, 4.94g aluminum oxide, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 6h and the ball milling speed is 450r / min. The slurry after ball milling is kept at 100℃ for 10h and dried. Then it is sintered once. The sintering temperature is 650℃, the holding time is 60min, and the heating rate is 4℃ / min. After the holding is completed and cooled, the first component of Li 1.4 Al 0.4 Ti 1.6 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 37.01g.

[0163] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 700 g of anhydrous ethanol, the grinding speed was 500 r / min, and the grinding time was 22 h. 1.67 g of grain growth inhibitor TiF4 was added after grinding for 20 h. The sand-milled slurry was kept warm at 150 ° C in a blast drying oven for 8 h and dried. The dried powder was subjected to a secondary sintering at a sintering temperature of 500 ° C, a holding time of 60 min, and a heating rate of 2 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 92.53 g, and the mass ratio of the first component to the second component was approximately 1:1.5.

[0164] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, then add 2.47g lithium carbonate, 5.35g titanium dioxide, and 7.70g ammonium dihydrogen phosphate and mix them using a planetary ball mill. The ball milling medium used is 430g anhydrous ethanol, the ball milling speed is 300r / min, and the ball milling time is 6h. The slurry after ball milling is dried in a blast drying oven at 120℃ for 10h to obtain a mixed powder. The powder is sintered in a tube furnace with nitrogen. The required air intake is 20ml / min, the sintering temperature is 600℃, the holding time is 100min, and the heating rate is 3℃ / min. After the holding is completed, the third component LiTiOPO is obtained. 4-y The first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer, wherein the D50 particle size of the first and second component LATP is 1.0 μm, the coating layer of the third component is 350 nm, and the mass ratio of the first component, the second component and the third component is 1:1.5:0.3.

[0165] Example 4

[0166] 1. Weigh 10.15g lithium carbonate, 63.23g ammonium dihydrogen phosphate, 21.95g titanium dioxide, 4.67g aluminum oxide, then add 200g deionized water as the ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 10h and the ball milling speed is 300r / min. The slurry after ball milling is kept at 100℃ for 16h and dried. Then it is sintered once. The sintering temperature is 600℃, the holding time is 60min, and the heating rate is 4℃ / min. After the holding is completed and cooled, the first component of Li 1.5 Al 0.5 Ti 1.5 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 34.87g.

[0167] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 210 g of anhydrous ethanol, the grinding speed was 2000 r / min, and the grinding time was 12 h. 2.09 g of grain growth inhibitor CaF2 was added after grinding for 11 h. The sand-milled slurry was kept at 180 ° C in a blast drying oven for 20 h and dried. The dried powder was subjected to a secondary sintering at a sintering temperature of 500 ° C, a holding time of 150 min, and a heating rate of 2 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 69.74 g, and the mass ratio of the first component to the second component was approximately 1:1.

[0168] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, then add 2.33g lithium carbonate, 5.04g titanium dioxide, and 7.26g ammonium dihydrogen phosphate and mix them using a planetary ball mill. The ball milling medium used is 425g anhydrous ethanol, the ball milling speed is 300r / min, and the ball milling time is 10h. The ball milled slurry is dried in a blast drying oven at 130°C for 8h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 150ml / min, the sintering temperature is 600°C, the holding time is 180min, and the heating rate is 0.5°C / min. After the holding is completed, the third component LiTiOPO is obtained. 4-y The first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer, wherein the D50 particle size of the first and second components LATP is 1.2 μm, the coating layer of the third component is 300 nm, and the mass ratio of the first component, the second component and the third component is 1:1:0.3.

[0169] Example 5

[0170] 1. Weigh 8.82g lithium carbonate, 63.41g ammonium dihydrogen phosphate, 24.95g titanium dioxide, 2.81g aluminum oxide, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 5h and the ball milling speed is 500r / min. The slurry after ball milling is kept at 120℃ for 12h and dried. Then sinter once. The sintering temperature is 550℃, the holding time is 45min, and the heating rate is 4℃ / min. After the holding is completed and cooled, the first component of Li 1.3 Al 0.3 Ti 1.7 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 40.26g.

[0171] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 210 g of anhydrous ethanol, the grinding speed was 1500 r / min, and the grinding time was 12 h. 1.51 g of grain growth inhibitor AlF3 was added after grinding for 11 h. The sand-milled slurry was kept at 150 ° C in a blast drying oven for 10 h and dried. The dried powder was subjected to a secondary sintering at a sintering temperature of 500 ° C, a holding time of 90 min, and a heating rate of 3 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 70.46 g, and the mass ratio of the first component to the second component was approximately 1:0.75.

[0172] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, then add 2.90g titanium dioxide and 8.35g ammonium dihydrogen phosphate to mix in a planetary ball mill. The ball milling medium used is 246g anhydrous ethanol, the ball milling speed is 400r / min, and the ball milling time is 10h. The ball milled slurry is dried in a blast drying oven at 100℃ for 12h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 100ml / min, the sintering temperature is 700℃, the holding time is 5min, and the heating rate is 4℃ / min. After the holding period is completed, the third component TiP2O is obtained. 7-z The first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer, wherein the D50 particle size of the first and second components LATP is 800nm, the coating layer of the third component is 250nm, and the mass ratio of the first component, the second component and the third component is 1:0.75:0.2.

[0173] Example 6

[0174] 1. Weigh 27.38g lithium dihydrogen phosphate, 39.76g diammonium hydrogen phosphate, 24.05g titanium dioxide, 8.81g aluminum carbonate, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 6h and the ball milling speed is 500r / min. The slurry after ball milling is kept at 100℃ for 15h and dried. Then it is sintered once. The sintering temperature is 500℃, the holding time is 100min, and the heating rate is 4℃ / min. After the holding is completed and cooled, the first component of Li 1.4 Al 0.4 Ti 1.6 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 32.68g.

[0175] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 220 g of anhydrous ethanol, the grinding speed was 800 r / min, and the grinding time was 12 h. 1.18 g of grain growth inhibitor AlF3 was added after grinding for 11 h. The sand-milled slurry was kept warm at 200 ° C in a blast drying oven for 2 h and dried. The dried powder was subjected to secondary sintering at a sintering temperature of 650 ° C, a holding time of 200 min, and a heating rate of 4 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 71.90 g, and the mass ratio of the first component to the second component was approximately 1:1.2.

[0176] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, then add 4.70g of titanium dioxide and 13.56g of ammonium dihydrogen phosphate to mix in a planetary ball mill. The ball milling medium used is 360g of anhydrous ethanol, the ball milling speed is 400r / min, and the ball milling time is 6h. The slurry after ball milling is dried in a blast drying oven at 120℃ for 12h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 50ml / min, the sintering temperature is 700℃, the holding time is 5min, and the heating rate is 4℃ / min. After the holding is completed, the third component TiP2O 7-z The first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer are LATP, wherein the D50 particle size of the first and second components LATP is 400nm, the coating layer of the third component is 100nm, and the mass ratio of the first component, the second component and the third component is 1:1.2:0.4.

[0177] Example 7

[0178] 1. Weigh 11.65g lithium carbonate, 51.68g phosphorus pentoxide, 32.95g titanium dioxide, 3.71g aluminum oxide, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 6h and the ball milling speed is 400r / min. The slurry after ball milling is kept at 100℃ for 24h and dried. Then it is sintered once. The sintering temperature is 550℃, the holding time is 30min, and the heating rate is 6℃ / min. After the holding is completed and cooled, the first component of Li 1.3 Al 0.3 Ti 1.7 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 33.23g.

[0179] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 300 g of anhydrous ethanol, the grinding speed was 1000 r / min, and the grinding time was 12 h. 3.00 g of grain growth inhibitor TiF4 was added after grinding for 11 h. The sand-milled slurry was kept warm at 200 ° C in a blast drying oven for 15 h and dried. The dried powder was subjected to a secondary sintering at a sintering temperature of 580 ° C, a holding time of 100 min, and a heating rate of 2 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 93.05 g, and the mass ratio of the first component to the second component was approximately 1:1.8.

[0180] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, and then add 2.96g lithium carbonate, 6.40g titanium dioxide, and 9.22g ammonium dihydrogen phosphate to mix in a planetary ball mill. The ball milling medium used is 400g anhydrous ethanol, the ball milling speed is 300r / min, and the ball milling time is 10h. The slurry after ball milling is dried in a blast drying oven at 80℃ for 12h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 150ml / min, the sintering temperature is 600℃, the holding time is 100min, and the heating rate is 4℃ / min. After the holding is completed, the third component LiTiOPO is obtained. 4-y The first component LATP of the oxygen defect coating layer and the second component fluorine-doped LATP, wherein the D50 particle size of the first and second components LATP is 600nm, the coating layer of the third component is 200nm, and the mass ratio of the first component, the second component and the third component is 1:1.8:0.4.

[0181] Example 8

[0182] 1. Weigh 8.96g lithium carbonate, 89.60g titanium pyrophosphate, 1.93g titanium dioxide, 4.94g aluminum oxide, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 6h and the ball milling speed is 450r / min. The slurry after ball milling is kept at 100℃ for 10h and dried. Then it is sintered once. The sintering temperature is 650℃, the holding time is 60min, and the heating rate is 4℃ / min. After the holding is completed and cooled, the first component of Li 1.4 Al 0.4 Ti 1.6 (PO4)3 material, unreacted raw materials and transition products, the sintered product was subjected to standardless quantitative analysis to obtain the first component LATP of 37.01g.

[0183] 2. All the products of the primary sintering were crushed, and the crushed powder was sand milled using a sand mill. The sand milling medium used was 700 g of anhydrous ethanol, the grinding speed was 500 r / min, and the grinding time was 22 h. 1.67 g of grain growth inhibitor TiF4 was added after grinding for 20 h. The sand-milled slurry was kept warm at 150 ° C in a blast drying oven for 8 h and dried. The dried powder was subjected to a secondary sintering at a sintering temperature of 500 ° C, a holding time of 60 min, and a heating rate of 2 ° C / min. After cooling after the holding was completed, the first component LATP and the second component fluorine-doped LATP were obtained. The total product was weighed to be 92.53 g, and the mass ratio of the first component to the second component was approximately 1:1.5.

[0184] 3. Grind and crush the LATP of the first component after secondary sintering and the fluorine-doped LATP of the second component, then add 10.00g of titanium dioxide and 28.79g of ammonium dihydrogen phosphate in a planetary ball mill for mixing. The ball milling medium used is 360g of anhydrous ethanol, the ball milling speed is 400r / min, and the ball milling time is 6h. The ball milled slurry is dried in a blast drying oven at 120℃ for 12h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 200ml / min, the sintering temperature is 700℃, the holding time is 60min, and the heating rate is 4℃ / min. After the holding period, the third component TiP2O is obtained. 7-z The first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer, wherein the D50 particle size of the first and second components LATP is 1.0 μm, the coating layer of the third component is 400 nm, and the mass ratio of the first component, the second component and the third component is 1:0.5:0.5.

[0185] Comparative Example 1

[0186] Direct synthesis of LATP solid electrolyte

[0187] 1. Weigh 8.96g lithium carbonate, 89.60g titanium pyrophosphate, 1.93g titanium dioxide, 4.94g aluminum oxide, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 6h and the ball milling speed is 450r / min. The slurry after ball milling is kept at 100℃ for 10h and dried. Then it is sintered once. The sintering temperature is 950℃, the holding time is 720min, and the heating rate is 4℃ / min. After the holding is completed and cooled, the first component of Li 1.4 Al 0.4 Ti 1.6 (PO4)3 material.

[0188] Comparative Example 2

[0189] Synthesis of LATP and fluorine-doped LATP materials by secondary sintering

[0190] 1. Preparation scheme The first two steps of Example 1 are the same, and the third component coating design in the third step is not performed.

[0191] Comparative Example 3

[0192] Direct synthesis of LATP materials does not require the design of a second component, and the third component material is directly synthesized in situ on the surface of the directly synthesized material.

[0193] 1. Weigh 8.96g lithium carbonate, 89.60g titanium pyrophosphate, 1.93g titanium dioxide, 4.94g aluminum oxide, then add 200g anhydrous ethanol ball milling medium and use a planetary ball mill for ball milling. The ball milling time is 6h and the ball milling speed is 450r / min. The slurry after ball milling is kept at 100℃ for 10h and dried. Then it is sintered once. The sintering temperature is 950℃, the holding time is 720min, and the heating rate is 4℃ / min. After the holding is completed and cooled, the first component of Li 1.4 Al 0.4 Ti 1.6 (PO4)3 material.

[0194] 2. Grind and crush the LATP of the first component after secondary sintering, then add 1.39g of alumina and 4.39g of ammonium dihydrogen phosphate and mix them using a planetary ball mill. The ball milling medium used is 210g of anhydrous ethanol, the ball milling speed is 200r / min, and the ball milling time is 15h. The ball milled slurry is dried in a blast drying oven at 80℃ for 12h to obtain a mixed powder. The powder is sintered in a tube furnace with argon gas. The required air intake is 10ml / min, the sintering temperature is 400℃, the holding time is 200min, and the heating rate is 4℃ / min. After the holding is completed, the third component AlPO is obtained. 4-xThe first component LATP and the second component fluorine-doped LATP of the oxygen defect coating layer have a mass ratio of the first component to the third component of 1.5:0.1.

[0195] Comparative Example 4

[0196] In the in-situ generated coating of the third component, no inert gas is introduced during the sintering process, and the sintering is carried out in an air environment. The remaining steps are the same as those in embodiment 1.

[0197] Comparative Example 5

[0198] In this solution, the third component is directly synthesized and added without in-situ coating, and ultimately a three-component mixture of the first component, the second component, and the third component is formed.

[0199] Compared with Example 1, the first two steps are the same. In the third step, 13.9g of aluminum oxide and 43.9g of ammonium dihydrogen phosphate are mixed using a planetary ball mill. The ball milling medium used is 210g of anhydrous ethanol, the ball milling speed is 200r / min, and the ball milling time is 15h. The slurry after ball milling is dried in a blast drying oven at 80°C for 12h to obtain a mixed powder. The powder is sintered in a tube furnace by passing argon gas. The required air intake is 10ml / min, the sintering temperature is 400°C, the holding time is 200min, the heating rate is 4°C / min, and the third component AlPO is obtained after the holding is completed. 4-x Oxygen defect material, and then 4.65g was mechanically mixed with the LATP prepared in the first two steps to obtain a three-component composite solid electrolyte.

[0200] Battery application and testing:

[0201] 1. Cathode coating

[0202] The dry method adopted in the present invention is to coat the positive electrode. The positive electrode active material adopted is NCM811. The added solid electrolyte coating layer accounts for 2wt‰ of the active material. The active material and the solid electrolyte are added to a ball mill and ball milled using a planetary ball mill. The ball mill speed used is 500r / min and the ball milling time is 8h. The ball-milled powder is passed through a 400-mesh sieve to obtain a positive electrode active material precursor with a coating layer. The precursor is heat-treated at 450°C in a muffle furnace and kept warm for 4h with a heating rate of 4°C / min. After the insulation is completed and cooled, the positive electrode active material coated with a solid electrolyte is obtained.

[0203] In an argon glove box with a water and oxygen content of less than 0.01 ppm, a 2032 button battery was prepared using the prepared NCM811 coated with a solid electrolyte as the positive electrode, a metal lithium sheet as the negative electrode, 1M LiPF6 dissolved in a mixed solution of ethylene carbonate (EC) / dimethyl carbonate (DMC) / diethyl carbonate (EMC) (the volume ratio is 1:1:1) as the electrolyte, and polypropylene as the separator.

[0204] 2. Positive electrode mixing

[0205] This solution uses NCM811 as the positive electrode active material. During the positive electrode homogenization process, the added material ratio of NCM811: solid electrolyte: SP: PVDF is 94.8%: 2%: 2%: 2.2%. The above positive electrode sheet is used to assemble a 2032 button battery. The assembly steps are the same as application 1.

[0206] 3. Diaphragm coating

[0207] The prepared solid electrolyte was crushed and ground and mixed into an aqueous slurry with a solid content of 20% using a disperser. A polypropylene diaphragm was selected as the base membrane and the solid electrolyte aqueous slurry was used to coat the diaphragm on both sides. The coating layer thickness was 2 μm. The coated diaphragm was assembled into a 2032 button battery. The assembly steps were the same as those in Application 1.

[0208] The prepared button battery was subjected to charge and discharge tests and cycle performance at a rate of 0.2C in the range of 3 to 4.2V, as well as charge and discharge performance at different rates. After formation, the battery was subjected to EIS impedance testing.

[0209] See FIG1 , which is an XRD phase spectrum of the third component oxygen defect coating layer prepared in an embodiment of the present disclosure.

[0210] See Figure 2, which is a diagram of the first charge and discharge cycle of a battery after the LATP composite solid electrolyte prepared in Example 1 of the present disclosure is mixed with the positive electrode.

[0211] See Table 1, which shows the electrochemical performance data of button-type batteries assembled with positive electrode coatings according to the embodiments of the present disclosure and the comparative example.

[0212] Table 1

[0213] From the electrochemical performance comparison of the button-type batteries of the embodiment and the comparative example in Table 1, it can be seen that the internal resistance is reduced because the third coating layer with oxygen defects accelerates the transmission of electrons in the positive electrode, thereby reducing the internal resistance of the battery. Secondly, due to the good structural chemical stability and suppression of HF generation of the solid electrolyte prepared by this scheme, the prepared battery has good cycle stability and capacity retention during long cycles. In addition, due to the synergistic effect of the three components, it has a good effect on improving and stabilizing the battery capacity. Therefore, the solid electrolyte prepared by this scheme has excellent electrochemical performance and application diversity in battery applications.

[0214] The above is a detailed introduction to a lithium oxide composite solid electrolyte, preparation method and application provided by the present disclosure. Specific examples are used herein to illustrate the principles and implementation methods of the present disclosure. The description of the above embodiments is only used to help understand the method and core ideas of the present disclosure, including the best mode, and also enables any technician in the field to practice the present disclosure, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present disclosure, several improvements and modifications can be made to the present disclosure, and these improvements and modifications also fall within the scope of protection of the claims of the present disclosure. The scope of patent protection of the present disclosure is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that are not substantially different from the literal description of the claims, then these other embodiments should also be included in the scope of the claims. Industrial Applicability

[0215] In summary, the present disclosure provides a lithium oxide composite solid electrolyte, preparation method and application. The lithium oxide solid electrolyte provided by the present disclosure, which can conduct ions and electrons at the same time, has a small particle size, excellent structural chemical stability, good hydrophobicity, and multiple applications. In battery applications, it can increase the capacity of positive and negative electrodes, provide better protection for the positive and negative electrodes, and improve the battery's charge and discharge capacity and cycle stability. The preparation method of the LATP composite solid electrolyte material, after multi-step sintering, the prepared material has a small particle size and uniform size. In the positive electrode application of the battery material, it can fully fill the gaps, accelerate the transmission of lithium ions in the positive electrode, and improve the battery's charge and discharge capacity; and it can also effectively control the content of the three components and the oxygen defect content by controlling the preparation process. Different adjustments can be made for different applications, so that a solid electrolyte can meet a variety of applications. The preparation method is simple and easy, the conditions are mild, the controllability is strong, the stability is good, and it is easier to promote and apply industrial production.

Claims

1. AlPO with oxygen defects 4-x 、TiP2O 7-y and LiTiOPO 4-z Application of one of them in LATP composite solid electrolyte material; in, 0<x<4, 0<y<7, 0<z<4.

2. The use according to claim 1, characterized in that The application is specifically the application as a coating layer of a LATP composite solid electrolyte material; The thickness of the coating layer is 50 to 400 nm; The LATP composite solid electrolyte material is specifically a LATP composite solid electrolyte material with an oxygen defect coating layer; The LATP composite solid electrolyte material further includes LATP and fluorine-doped LATP arranged in the coating layer.

3. The use according to claim 1, characterized in that The applications include promoting electron transport and improving the electronic conductivity of LATP composite solid electrolytes; The applications include improving the charge and discharge capabilities of batteries using LATP composite solid electrolytes; The applications include suppressing HF formation in batteries using LATP composite solid electrolytes.

4. A LATP composite solid electrolyte material, characterized in that: The LATP composite solid electrolyte has a core-shell structure, including a LATP material core and an oxygen defect shell; The oxygen defect shell is AlPO 4-x 、TiP2O 7-y or LiTiOPO 4-z ; Among them, 0<x<4, 0<y<7, 0<z<4.

5. The LATP composite solid electrolyte material according to claim 4, characterized in that The LATP material core includes LATP and fluorine-doped LATP; The D50 particle size of the LATP material core is 0.2-1.5 μm.

6. The LATP composite solid electrolyte material according to claim 5, characterized in that The mass ratio of the LATP to the fluorine-doped LATP is 1:(0.5-2); The mass ratio of the LATP to the oxygen defect shell is 1:(0.1-0.5); In the fluorine-doped LATP, the doping mass content of fluorine is 0.25‰ to 3.6‰.

7. A method for preparing a LATP composite solid electrolyte material, characterized in that: The following steps are involved: 1) mixing a first lithium source, a first aluminum source, a first titanium source, and a first phosphorus source to obtain a LATP precursor, and then performing a first sintering to obtain a mixture containing LATP; 2) grinding and mixing the mixture containing LATP obtained in the above step and the fluorine-containing grain growth inhibitor, and then sintering for a second time to obtain a composite of LATP and fluorine-doped LATP; 3) Grinding and mixing two or more of the second lithium source, the second aluminum source, the second titanium source, and the second phosphorus source with the LATP and fluorine-doped LATP complex obtained in the above step again, and then sintering for a third time under a protective atmosphere to obtain a LATP composite solid electrolyte material with an in-situ oxygen defect coating layer.

8. The preparation method according to claim 7, characterized in that The first lithium source and the second lithium source each independently include one or more of lithium carbonate, lithium hydroxide and lithium dihydrogen phosphate; The first aluminum source and the second aluminum source each independently include one or more of aluminum oxide, aluminum carbonate and aluminum hydroxide; The first titanium source and the second titanium source each independently comprise titanium dioxide and / or titanium hydroxide; The first phosphorus source and the second phosphorus source independently include one or more of ammonium dihydrogen phosphate, diammonium hydrogen phosphate, titanium pyrophosphate and phosphorus pentoxide.

9. The preparation method according to claim 7 or 8, characterized in that In the step 1), the mixing method includes ball milling; The mixing time is 3 to 15 hours; The mixing speed is 200-500 r / min; The chemical formula of the LATP is Li 1+x Al x Ti 2-x (PO4)3, where 0.3≤x≤0.

6.

10. The preparation method according to any one of claims 7 to 9, characterized in that: The temperature of the first sintering is 450-700°C; The heating rate of the first sintering is 1-6°C / min; The holding time of the first sintering is 30 to 360 minutes; The LATP-containing mixture includes LATP, remaining raw materials and transition products.

11. The preparation method according to any one of claims 7 to 10, characterized in that: The fluorine-containing grain growth inhibitor includes one or more of calcium fluoride, aluminum fluoride and titanium tetrafluoride; The mass ratio of the grain growth inhibitor to the mixture containing LATP is (0.01-0.1):

1.

12. The preparation method according to any one of claims 7 to 11, characterized in that: In the step 2), the rotation speed of the grinding and mixing is 200 to 2000 r / min; The grinding and mixing time is 1 to 12 hours.

13. The preparation method according to any one of claims 7 to 12, characterized in that: The temperature of the second sintering is 450-700°C; The heating rate of the second sintering is 1-6°C / min; The holding time of the second sintering is 20 to 300 minutes.

14. The preparation method according to any one of claims 7 to 13, characterized in that: In the step 3), the rotation speed of the grinding and mixing is 200 to 500 r / min; The grinding and mixing time is 3 to 15 hours.

15. The preparation method according to any one of claims 7 to 14, characterized in that: The temperature of the third sintering is 400-700°C; The heating rate of the third sintering is 0.5-4°C / min; The holding time of the third sintering is 5 to 200 minutes.

16. Use of the LATP composite solid electrolyte material according to any one of claims 1 to 3, the LATP composite solid electrolyte material according to any one of claims 4 to 6, or the LATP composite solid electrolyte material prepared by the preparation method according to any one of claims 7 to 15 in a solid-state battery.

17. The use according to claim 16, characterized in that The solid battery includes an all-solid-state lithium battery; The application is application in a solid-state battery positive electrode; The application in the positive electrode of a solid-state battery is specifically the application as a mixed ion conductor in the positive electrode; The application methods include coating and / or blending.

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