Lithium titanium aluminum phosphate electrolyte material and highly safe rechargeable lithium battery

Abstract

A lithium titanium aluminum phosphate electrolyte material and a rechargeable high-safety lithium battery, wherein the mass content of the lithium titanium aluminum phosphate is 95% to 100%, and the electrolyte of the lithium battery contains lithium titanium aluminum phosphate, and the chemical formula of the lithium titanium aluminum phosphate is Li 1+z+3u Al z Ti 2-z M 3u (P 1-u O4)3 (abbreviated as LATP). LATP materials with a high dielectric constant correspond to LATP with a high lithium content, and have high resistance, low capacity, and low retention rate. Materials with a low dielectric constant correspond to LATP with a low lithium content, and have a low lithium ion transport number, low capacity, and low retention rate. Materials with a high elastic modulus have high hardness, poor intergranular contact, relatively high resistance, and low battery capacity and retention rate. Materials with a low elastic modulus have low hardness, good intergranular contact, relatively low resistance, and high battery capacity and retention rate. Therefore, the rechargeable high-safety lithium battery has a dielectric constant y and elastic modulus x of 40 or less.

Description

[Technical Field]

[0001] The present disclosure relates to the field of new energy technology, and in particular to a lithium titanium aluminum phosphate electrolyte material and a highly safe rechargeable lithium battery. (CROSS-REFERENCE TO RELATED APPLICATIONS) This disclosure claims priority to a Chinese application filed with the China Patent Office on August 29, 2023, bearing application number 202311094835.3 and entitled "Rechargeable High-Safety Lithium Battery," the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Conventional lithium-ion batteries use organic electrolyte solutions with relatively low ionic resistance as the electrolyte. However, due to the flammability and leakiness of organic electrolytes, these can pose safety issues and reduce specific energy. These problems can be avoided by using all-solid-state batteries with non-flammable solid electrolytes.

[0003] The solid electrolyte lithium titanium aluminum phosphate has advantages such as excellent mechanical properties, excellent electrochemical properties, high ionic conductivity, and excellent stability in air, contributing to the preparation of safe, high-energy-density solid-state lithium batteries. Experiments have shown that when lithium titanium aluminum phosphate is used as a solid electrolyte, its thermal stability above 800°C can improve the thermal stability and nail penetration safety of cells. However, some all-solid-state batteries with solid electrolytes have a problem of relatively high solid-state interface contact resistance, resulting in reduced capacity after long cycles. Summary of the Invention

[0004] The present disclosure aims to provide a lithium titanium aluminum phosphate electrolyte material and a highly safe rechargeable lithium battery that can improve or solve the above problems. To achieve the above objectives, the present disclosure adopts the following technical solutions. The present disclosure provides a lithium aluminum titanium phosphate electrolyte material. The mass content of lithium aluminum titanium phosphate in the lithium aluminum titanium phosphate electrolyte material is 95% to 100%, and the chemical formula of lithium aluminum titanium phosphate is Li 1+z+3u Al z Ti 2-z M 3u (P 1-u O4)3, where M is any one or more selected from Ti, Zr, Hf, Si, Ge, and Sn, z satisfies 0 < z < 1, u satisfies 0 ≤ u ≤ 0.2, and the lithium aluminum titanium phosphate has an elastic modulus x of 56 GPa to 95 GPa, a dielectric constant y of 195 to 400 (unit F / m), and the dielectric constant y and the elastic modulus x satisfy the relational expression of 40 < y - 2.79x ≤ 120. In a selectable embodiment, the lithium aluminum titanium phosphate satisfies the relational expression that the dielectric constant y and the elastic modulus x satisfy 50 ≤ y - 2.79x ≤ 100. In a selectable embodiment, the elastic modulus x of the lithium aluminum titanium phosphate satisfies 60 ≤ x < 95.

[0005] The present disclosure provides a rechargeable high-safety lithium battery. The lithium battery includes a positive electrode, a negative electrode, and an electrolyte located between the positive electrode and the negative electrode. The electrolyte includes lithium aluminum titanium phosphate, and the chemical formula of lithium aluminum titanium phosphate is Li 1+z+3u Al z Ti 2-z M 3u (P 1-u O4)3 (abbreviated as LATP), where M is any one or more selected from Ti, Zr, Hf, Si, Ge, and Sn, z satisfies 0 < z < 1, u satisfies 0 ≤ u ≤ 0.2, and the lithium aluminum titanium phosphate has a dielectric constant y and an elastic modulus x that satisfy the relational expression of 40 < y - 2.79x ≤ 120.

[0006] The present disclosure provides a rechargeable high-safety lithium battery. The lithium battery includes a positive electrode, a negative electrode, and an electrolyte positioned between the positive electrode and the negative electrode. The electrolyte contains lithium aluminum titanium phosphate, and the content of lithium aluminum titanium phosphate in the electrolyte is 95% - 100%. The chemical formula of lithium aluminum titanium phosphate is Li 1+z+3u Al z Ti 2-z M 3u (P 1-u O4)3, where M is any one or more selected from Ti, Zr, Hf, Si, Ge, and Sn, z satisfies 0 < z < 1, u satisfies 0 ≤ u ≤ 0.2, and lithium aluminum titanium phosphate has an elastic modulus x of 56 GPa - 95 GPa, a dielectric constant y of 195 - 400, and the dielectric constant y and the elastic modulus x satisfy the relational expression 40 < y - 2.79x ≤ 120.

[0007] The lithium battery is a solid battery and / or a semi-solid battery. In the solid battery, cold pressing is performed on lithium aluminum titanium phosphate to form a sheet to obtain a solid electrolyte. In the semi-solid battery, lithium aluminum titanium phosphate is coated on a separator.

[0008] In an alternative embodiment, lithium aluminum titanium phosphate satisfies the relational expression 50 ≤ y - 2.79x ≤ 100 for the dielectric constant y and the elastic modulus x.

[0009] In an alternative embodiment, the elastic modulus x of lithium aluminum titanium phosphate satisfies 60 ≤ x < 95. In an alternative embodiment, the positive electrode active material in the positive electrode powder of the positive electrode is coated with lithium aluminum titanium phosphate, and / or the negative electrode powder of the negative electrode is doped with lithium aluminum titanium phosphate. In an alternative embodiment, the lithium battery is a lithium-ion battery, and the positive electrode powder contains, by mass fraction, 80% - 99% of a positive electrode active material, 0.2% - 20% of a conductive agent, 0.2% - 20% of a binder, and 0% - 20% of an additive.

[0010] In an alternative embodiment, the negative electrode powder contains, by mass fraction, 80% to 99% of a negative electrode active material, 0.2% to 20% of a conductive agent, 0.2% to 20% of a binder, and 0% to 20% of an additive.

[0011] In an alternative embodiment, the lithium battery is a lithium-air battery, and the positive electrode powder includes 80% to 99% positive electrode active material, 0.5% to 20% conductive agent, 0.2% to 20% binder, and 0% to 20% additive.

[0012] In an alternative embodiment, the lithium battery is a lithium-sulfur battery, and the positive electrode powder includes 80% to 99% positive electrode active material, 0.2% to 20% conductive agent, 0.2% to 20% binder, and 0% to 20% additive.

[0013] In an alternative embodiment, the positive electrode active material is one or more selected from NCM, NCA, lithium-rich manganese-based materials, LFP, LiMO, S, FeS, FeS, LiS, and porous carbon materials, where M in LiMO is selected from Mn, Co, or Ni.

[0014] In an alternative embodiment, the negative electrode active material is one or more selected from metallic lithium, a lithium alloy, graphite, Si, SiO, SiC, and LTO. In an alternative embodiment, the conductive agent is one or more selected from carbon black, conductive graphite, carbon fiber, carbon nanotubes, graphene, carbon aerogel, and conductive carbon nitride.

[0015] In an alternative embodiment, the binder is one or more selected from polyvinylidene fluoride, polytetrafluoroethylene, carboxymethyl cellulose, styrene butadiene rubber, methyl cellulose, polyacrylic acid, polyacrylate, polyacrylonitrile.

[0016] In an alternative embodiment, the additive is one or more selected from oxides, sulfides, halides, and polymers.

[0017] In an alternative embodiment, the preparation process for coating the positive electrode active material with lithium titanium aluminum phosphate comprises: mixing the positive electrode active material and the additive and dispersing the mixture in absolute ethanol to obtain a positive electrode active material solution; and homogeneously mixing lithium titanium aluminum phosphate and a positive electrode active material solution to make the powder have a solid content of 20% to 50%, spray drying, setting the gas inlet temperature to 200 to 300°C and the gas outlet temperature to 100 to 200°C, and then performing a heat treatment at 500 to 800°C in an oxygen gas atmosphere for 2 to 24 hours to obtain a positive electrode active material coated with lithium titanium aluminum phosphate.

[0018] In alternative embodiments, the lithium battery includes a solid-state battery and / or a semi-solid-state battery, in which the lithium titanium aluminum phosphate is cold pressed into a sheet to obtain a solid electrolyte, and in which the lithium titanium aluminum phosphate is applied to a separator in a semi-solid-state battery.

[0019] In alternative embodiments, the production process for lithium titanium aluminum phosphate includes any one of dry mix sintering, liquid phase spray sintering, sol-gel sintering, melt quench sintering, sputtering sintering, vapor deposition sintering, electrospinning sintering, and vapor / electrochemical growth sintering. The present disclosure has the following beneficial effects:

[0020] The rechargeable high-safety lithium battery according to the present disclosure includes a positive electrode, a negative electrode, and lithium titanium aluminum phosphate located between the positive electrode and the negative electrode, the lithium titanium aluminum phosphate having a chemical formula of Li 1+z+3u Al z Ti 2-z M 3u (P 1-uIt is Li₁.₅Al₀.₅Ti₁.₅(PO₄)₃ (abbreviated as LATP). The LATP material with a high dielectric constant corresponds to LATP with a high lithium content (z = 0.5), has a high resistance, and low capacitance and retention rate. The material with a low dielectric constant corresponds to LATP with a low lithium content (z = 0.1), has a low lithium ion transport rate, and low capacitance and retention rate. The material with a high elastic modulus has a high hardness, poor intergranular contact, a relatively high resistance, and low battery capacitance and retention rate. The material with a low elastic modulus has a low hardness, good intergranular contact, a relatively low resistance, and high battery capacitance and retention rate. A solid lithium battery with high capacitance and capacitance retention rate requires an appropriate dielectric constant and elastic modulus. The rechargeable high-safety lithium battery according to the present disclosure satisfies the relational expression of 40 < y - 2.79x ≤ 120 for the dielectric constant y and the elastic modulus x. A solid lithium battery that satisfies this condition has a high capacitance and capacitance retention rate.

[0021] To more clearly explain the technical solutions of the embodiments of the present disclosure, the drawings used in the embodiments will be briefly described below. The drawings to be described only show some embodiments of the present disclosure and do not limit the scope of the present disclosure.

Brief Description of the Drawings

[0022] [Figure 1] SEM photograph of the LATP-1 solid electrolyte according to Example 1. [Figure 2] SEM photograph of the cross-section of the NCM-L composite material coated with NCM9055 with LATP-1 according to Example 1. [Figure 3] An enlarged view of FIG. 2. [Figure 4] SEM photograph of the one coated with NCM9055 with LATP-3 according to Example 3. [Figure 5] SEM photograph of the cross-section of the one coated with NCM9055 with LATP-3 according to Example 3. [Figure 6] SEM photograph of the PE separator. [Figure 7] SEM photograph of the cross-section of the PE separator coated with two layers of LATP-PVDF according to Example 4. [Figure 8] FIG. 8 is an enlarged cross-sectional view of FIG. 7. [Figure 9] 1 is a graph showing the relationship between the elastic modulus and the dielectric constant of an LATP-based inorganic solid electrolyte. [Figure 10] 10 is a constant current charge / discharge curve of Li-LATP@C according to Example 3. [Figure 11] 1 shows the XRD diffraction spectrum of the LATP nanomaterial prepared in Example 3. [Figure 12] 1 shows XRD diffraction spectra of NCM9055 coated with LATP according to Examples 1 to 4. [Figure 13] 1 shows XPS spectra of materials obtained by coating NCM9055 with LATP according to Examples 1 to 3. [Figure 14] 1 shows XPS spectra of materials obtained by coating NCM9055 with LATP according to Examples 1 to 3. [Figure 15] 1 shows XPS spectra of materials obtained by coating NCM9055 with LATP according to Examples 1 to 3. DETAILED DESCRIPTION OF THE INVENTION

[0023] For example, the terms used in this specification are understood as follows:

[0024] "Prepared by" has the same meaning as "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, imply a non-exclusive inclusion. For example, a composition, step, method, product, or device that comprises listed elements may include not only those elements, but also other elements not expressly listed or inherent in those compositions, steps, methods, products, or devices.

[0025] The phrase "consisting of" excludes any unspecified element, step, or composition. When used in a claim, the phrase means that the claim is closed-form and does not include any materials other than those recited, except for common impurities of interest. When the phrase "consisting of" appears in a clause of claim content rather than in the subject matter, it limits the claims to only those elements recited in that clause and does not exclude other elements from the claim as a whole.

[0026] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range limited by a series of preferred upper and lower limits, it should be understood that all ranges, in any combination of any upper or preferred range value and any lower or preferred range value, are specifically disclosed, whether or not a separate disclosure is made. For example, if a range of "1 to 5" is disclosed, it is understood that the described range includes ranges such as "1 to 4," "1 to 3," "1 to 2," "1 to 2 and 4 to 5," "1 to 3 and 5," etc. Numerical ranges described herein include the critical values ​​and all integers and fractions within the range, unless otherwise specified.

[0027] In these examples, parts and percentages are calculated by weight unless otherwise specified.

[0028] "Parts by mass" is a basic unit of measurement that expresses the mass ratio relationship between multiple components, and 1 part can represent any unit mass, for example, 1 g or 2.689 g. If the parts by mass of component A are a parts and the parts by mass of component B are b parts, this represents that the ratio of the mass of component A to the mass of component B is a:b, or that the mass of component A is aK and the mass of component B is bK (where K is an arbitrary number representing a multiplicative factor). Note that, unlike % by mass, the total parts by mass of all components does not necessarily equal 100 parts. "And / or" indicates that at least one of the stated circumstances occurs. For example, A and / or B includes "A and B" and "A or B."

[0029] The following specific examples are provided to further illustrate the present disclosure. Those skilled in the art will appreciate that the following examples are merely illustrative of the present disclosure and are not intended to limit the scope of the present disclosure. In the examples, specific conditions are not specified, and conventional conditions or manufacturer-recommended conditions may be used. For reagents or equipment whose manufacturers are not specified, conventional commercially available products may be used.

[0030] Example 1 (1) VC Mixing (using a VC mixer) Using a high-temperature solid-state reaction method, the chemical formula is Li 1.4 Al 0.4 Ti 1.6 The lithium titanium aluminum phosphate solid electrolyte powder (PO4)3 was prepared. The preparation process involved selecting LiOH (or Li2CO3), Al2O3, TiO2, and NH4H2PO4 as raw materials in a molar ratio of Li, Al, Ti, and P of 1.6:0.4:1.6:3, adding 15 wt% excess LiOH (or Li2CO3), mixing thoroughly in a VC mixer, and sintering at 850°C for 12 hours with a heating rate of 4°C / min. After sintering, the powder was crushed, polished (ball milling and sanding), dried, sieved, and dewatered to obtain 300nm Li particles. 1.4 Al 0.4 Ti 1.6 The (PO4)3 powder was obtained and recorded as LATP-1, and its SEM photograph is shown in Figure 1.

[0031] (2) NCM9055(LiNi 0.9 Co 0.05 Mn 0.05O2), LATP-1, and Al2O3 were mixed uniformly in a 98:1:1 ratio and then heat-treated at 550°C for 12 hours in an oxygen gas atmosphere to obtain an NCM-L composite material in which NCM9055 was coated with LATP-1. Figure 2 shows an SEM image of the cross section, and Figure 3 is an enlarged view of the spherical portion in Figure 2. NCM-L, Super P, and PVDF were then weighed in a 95:3:2 ratio and polished to prepare the positive electrode active material. Graphite, LATP-1, acetylene black, CMC, and SBR were weighed in a 95:0.5:2.5:1:1 ratio and thoroughly polished to prepare the negative electrode active material.

[0032] (3) An appropriate amount of LATP-1 powder was weighed and cold-pressed at a pressure of 50 MPa for 1 minute to obtain a thin sheet with a diameter of 14 mm and a thickness of 500 μm. Positive and negative active materials were placed on both sides of the LATP-1 sheet material and spread evenly until the areal density of the positive and negative active materials was 2 mg / cm. 2 and 3 mg / cm 2 The sample was placed in a Swagelok cell and subjected to a constant current charge / discharge test at a mold pressure of 5 Nm. The voltage for the constant current charge / discharge was 2.0 V to 4.3 V, and the current was 0.05 C.

[0033] Example 2 (1) Using the liquid phase spray mixing high temperature solid phase reaction method, the chemical formula is Li 1.6 Al 0.4 Ti 1.6 Si 0.2 (P 0.93A lithium silicon titanium aluminum phosphate solid electrolyte powder (O4)3 was prepared. The preparation process involved selecting LiOH (or Li2CO3), Al2O3, SiO2, TiO2, and NH4H2PO4 as raw materials in a molar ratio of Li, Al, Ti, Si, and P of 1.8:0.4:1.6:0.2:2.8, adding 15 wt% excess LiOH (or Li2CO3), thoroughly mixing in a ball mill, spray drying, and sintering at an inlet temperature of 220°C and an outlet temperature of 120°C to obtain a LATSP precursor. The resulting powder was then sintered at 850°C for 12 hours with a heating rate of 4°C / min. After sintering, the powder was milled, polished (ball milling and sanding), dried, sieved, and dewatered to obtain 350 nm Li particles. 1.6 Al 0.4 Ti 1.6 Si 0.2 (P 0.93 O4)3 powder was obtained and recorded as LATP-2.

[0034] (2) NCM9055, LATP-2, ZrO2, and Al2O3 were mixed in a ratio of 98:1:0.5:0.5 and then heat-treated at 600°C for 12 hours in an oxygen gas atmosphere to obtain an NCM-L composite material in which NCM9055 was coated with LATP-2. NCM-L, Super P, and PVDF were then weighed in a ratio of 95:3:2 and polished to prepare the positive electrode active material. Graphite, LATP-2, acetylene black, CMC, and SBR were weighed in a ratio of 95:0.5:2.5:1:1 and polished thoroughly to prepare the negative electrode active material.

[0035] (3) An appropriate amount of LATP-2 powder was weighed and cold-pressed at a pressure of 50 MPa for 1 minute to obtain a thin sheet with a diameter of 14 mm and a thickness of 500 μm. Positive and negative active materials were placed on both sides of the LATP-2 sheet and spread evenly until the areal density of the positive and negative active materials was 2 mg / cm. 2 and 3 mg / cm 2The sample was placed in a Swagelok cell and subjected to a constant current charge / discharge test at a mold pressure of 5 Nm. The voltage for the constant current charge / discharge was 2.0 V to 4.3 V, and the current was 0.05 C.

[0036] Example 3 (1) Using the sol-gel method, the chemical formula is Li 1.8 Al 0.4 Ti 1.6 Zr 0.4 (P 0.86 A lithium zirconium titanium aluminum phosphate solid electrolyte powder (LATP-3) was prepared. The preparation process involved selecting LiNO3, Al(NO3)3 9H2O, Ti(OC4H9)4, Zr(NO3)4, and NH4H2PO4 as raw materials in a molar ratio of Li:Al:Ti:Zr:P of 2.0:0.4:1.6:0.4:2.6. LiNO3 was added in an excess of 10 wt%, and citric acid was used as a chelating agent and ammonia water as a pH adjuster. The resulting mixture was thoroughly stirred in a water bath at 80°C to obtain the LATP-3 precursor. The resulting mixture was then sintered at 700°C for 8 hours with a heating rate of 4°C / min. After sintering, the powder was milled, polished (ball milling and sanding), dried, sieved, and dewatered to obtain 250nm Li phosphate particles. 1.8 Al 0.4 Ti 1.6 Zr 0.4 (P 0.86 O4)3 powder was obtained and recorded as LATP-3.

[0037] (2) NCM9055, TiO2, and Al2O3 were dispersed in ethanol in a ratio of 98:0.5:0.5 and thoroughly stirred. Then, 1 wt% of LATP-3 precursor was mixed uniformly by ball milling. The powder was spray-dried to a solid content of 40%. The gas inlet temperature was set to 220°C, the gas outlet temperature to 120°C, and the mixture was heat-treated at 700°C for 12 h in an oxygen atmosphere to obtain an NCM-L composite in situ coated with LATP-3. The SEM image is shown in Figure 4, and the cross-sectional SEM image is shown in Figure 5. NCM-L, Super P, and PVDF were then weighed in a ratio of 95:3:2, polished, and used as the cathode active material.

[0038] (3) An appropriate amount of LATP-3 powder was weighed and cold-pressed at a pressure of 30 MPa for 1 minute to obtain a thin sheet with a diameter of 14 mm and a thickness of 500 μm. The positive electrode active material from step (2) was placed on one side of the LATP-3 sheet and spread evenly until the areal density of the positive electrode active material was 2 mg / cm. 2 The sample was placed in a Swagelok cell and subjected to a constant current charge / discharge test at a voltage of 2.0V to 4.3V and a current of 0.05C.

[0039] Example 4 (1) VC Mixing (using a VC mixer) Using a high-temperature solid-state reaction method, the chemical formula is Li 1.3 Al 0.3 Ti 1.7The lithium titanium aluminum phosphate solid electrolyte powder (PO4)3 was prepared. The preparation process involved selecting LiOH (or Li2CO3), Al2O3, TiO2, and NH4H2PO4 as raw materials in a molar ratio of Li, Al, Ti, and P of 1.5:0.3:1.7:3, adding 15 wt% excess LiOH (or Li2CO3), thoroughly mixing them in a VC mixer, and sintering them at 850°C for 12 hours with a heating rate of 4°C / min. After sintering, the powder was crushed, polished (ball milling and sanding), dried, sieved, and dewatered to obtain 300nm Li particles. 1.3 Al 0.3 Ti 1.7 (PO4)3 powder was obtained and recorded as LATP-4.

[0040] (2) NCM9055, LATP-4, ZrO2, and Al2O3 were uniformly mixed in a ratio of 98:1:0.6:0.4 and heat-treated at 650°C for 12 hours in an oxygen gas atmosphere to obtain an NCM-L composite material in which NCM9055 was coated with LATP-4. NCM-L, Super P, and PVDF were then weighed out in a ratio of 95:3:2, dispersed in NMP slurry, applied to Al foil, and vacuum-dried at 80°C for 12 hours to prepare a positive electrode. Graphite, LATP-4, acetylene black, CMC, and SBR were weighed out in a ratio of 95:0.5:2.5:1:1, dispersed in an aqueous slurry, applied to copper foil, and vacuum-dried at 100°C for 12 hours to prepare a negative electrode.

[0041] (3) An aqueous slurry with a solids content of 35% was prepared by dispersing an appropriate amount of LATP-4, CMC, SBR, and a wetting agent in water in a ratio of 95:1.5:1.5:2. After ball milling, the slurry was applied to a commercially available PE separator. An SEM image of the resulting PE separator is shown in Figure 6. The separator was 10 μm thick, with an LATP coating layer approximately 2 μm thick. A 1 μm-thick PVDF membrane was applied on top of the LATP coating layer to improve adhesion between the separator and the positive and negative electrodes of the battery. An SEM image of the cross section of the LATP-PVDF bilayer-coated PE separator is shown in Figure 7, and an enlarged cross section is shown in Figure 8. The separator was then thoroughly dried at 80 °C to obtain an LATP-coated separator (LATP-coated separator) with a thickness of 14.5 μm. A CR232 coin battery was assembled using the positive electrode plate, the LATP-coated separator (facing the positive electrode plate), and the negative electrode plate. The diameters of the positive and negative electrodes were 15 mm, the separator diameter was 20 mm, and the electrolyte was 1 mol / L LiPF6-EC / DEC / EMC. A charge-discharge test was performed on the battery at a constant current of 1 C. The voltage for the constant current charge-discharge was 2.5 V to 4.3 V, and the current was 1 C.

[0042] Example 5 1) VC Mixing (using a VC mixer) Using a high-temperature solid-state reaction method, the chemical formula is Li 1.7 Al 0.4 Ti 1.6 Si 0.3 (P 0.9 A lithium silicon titanium aluminum phosphate solid electrolyte powder (O4)3 was prepared. The preparation process involved selecting LiOH (or Li2CO3), Al2O3, SiO2, TiO2, and NH4H2PO4 as raw materials in a molar ratio of Li, Al, Ti, Si, and P of 2.0:0.4:1.6:0.3:2.7, adding 15 wt% excess LiOH (or Li2CO3), thoroughly mixing them in a VC mixer, and sintering them at 900°C for 12 hours with a heating rate of 4°C / min. After sintering, the powder was crushed, polished (ball milling and sanding), dried, sieved, and dewatered to obtain 280nm Li particles. 1.7 Al0.4 Ti 1.6 Si 0.3 (P 0.9 O4)3 powder was obtained and recorded as LATP-5.

[0043] (2) Nano-LATP-5 powder was taken and placed in a 5% sucrose solution, stirred at 1000 rpm for 5 h, and dried at 100 °C. It was then heat-treated at 850 °C for 12 h under a nitrogen gas atmosphere to obtain an LATP-coated LATP-C composite. KB600, LATP-C, Co3O4, multi-walled CNTs, and PVDF were weighed in a ratio of 93:3:2:1:1 and dispersed in an NMP slurry. After thorough stirring, the mixture was applied to a carbon-coated porous Al foil and vacuum-dried at 80 °C for 12 h to prepare a positive electrode plate.

[0044] (3) An aqueous slurry with a solids content of 35% was prepared by dispersing an appropriate amount of LATP-5, CMC, SBR, and a wetting agent in water in a ratio of 95:1.5:1.5:2. After ball milling, the slurry was applied to a commercially available Celgard separator, resulting in a separator with a thickness of 20 μm and an LATP coating layer of approximately 2 μm. A 1 μm-thick PVDF membrane was applied to the top of the LATP coating layer to improve adhesion between the separator and the positive and negative electrodes of the battery. The separator was then thoroughly dried at 80°C to obtain an LATP-coated separator with a thickness of 14.5 μm. A CR232 coin-type battery (with a porous cathode housing) was assembled using the positive electrode plate, the LATP-coated separator (facing the positive electrode plate), and a metallic lithium anode. The cathode and anode diameters were 15 mm, the separator diameter was 20 mm, and the electrolyte was 1 mol / L LiTFSI-TEG / DME. A charge-discharge test was performed at a constant current of 1 C in an oxygen gas atmosphere (humidity <10%). The voltage for the constant current charge-discharge was 2.0 V to 4.5 V, and the current was 1 C.

[0045] Example 6 (1) VC Mixing (using a VC mixer) Using a high-temperature solid-state reaction method, the chemical formula is Li 1.6 Al 0.4 Ti1.6 Ge 0.2 (P 0.93 A lithium germanium titanium aluminum phosphate solid electrolyte powder (GeTaO4)3 was prepared. The preparation process involved selecting LiOH (or Li2CO3), Al2O3, GeO2, TiO2, and NH4H2PO4 as raw materials in a molar ratio of Li, Al, Ti, Ge, and P of 1.8:0.4:1.6:0.2:2.8, adding 15 wt% excess LiOH (or Li2CO3), thoroughly mixing them in a VC mixer, and sintering them at 900°C for 12 hours with a heating rate of 4°C / min. After sintering, the powder was crushed, polished (ball milling and sanding), dried, sieved, and dewatered to obtain 320nm Li particles. 1.6 Al 0.4 Ti 1.6 Ge 0.2 (P 0.93 O4)3 powder was obtained and recorded as LATP-6.

[0046] (2) Nano-LATP-6 powder was taken and placed in a 5% citric acid solution, stirred at 2000 rpm for 5 h, and dried at 100 °C. It was then heat-treated at 850 °C for 12 h under a nitrogen gas atmosphere to obtain an LATP-coated LATP-C composite. S and KB (Ketjen Black) were mixed in a 3:1 ratio and uniformly polished. Then, heat treatment was performed in a vacuum tube furnace at 155 °C for 24 h to obtain an SC active material with a 60% S content. SC, LATP-C, multiwalled CNTs, and PVDF were weighed in a 93:3:2:2 ratio and dispersed in NMP slurry. After thorough stirring, the mixture was applied to a carbon-coated porous Al foil and vacuum-dried at 80 °C for 12 h to prepare a positive electrode plate.

[0047] (3) An appropriate amount of LATP-6, cellulose acetate, and a wetting agent were dispersed in water in a ratio of 95:3:2 to prepare an aqueous slurry with a solids content of 35%. After ball milling, the slurry was applied to a commercially available PE separator, resulting in a separator with a thickness of 12 μm and an LATP coating layer of approximately 2 μm. A 1 μm-thick PVDF membrane was applied to the top surface of the LATP coating layer to improve adhesion between the separator and the positive and negative electrodes of the battery. The separator was then thoroughly dried at 80°C to obtain an LATP-coated separator (separator coated with LATP) with a thickness of 14.5 μm. A CR232 coin cell battery was assembled using the above positive electrode plate, an LATP-coated separator (facing the positive electrode plate), and a metallic lithium negative electrode. The diameters of the positive and negative electrodes were 15 mm, the separator diameter was 20 mm, and the electrolyte was 1 mol / L LiTFSI-DME / DOL + 0.2% LiNO3. The electrolyte was in excess, and a charge-discharge test was performed at a constant current of 1 C. The voltage for the constant current charge-discharge was 1.7 V to 3.2 V, and the current was 1 C.

[0048] Example 7 This was the same as Example 4, except that the positive electrode was not coated with Al2O3, ZrO2, or LATP, and the negative electrode was not doped with LATP. Here, the Al content of the LATP material was z=0.4 and u=0 (Li 1+z+3u Al z Ti 2-z M 3u (P 1-u O4)3, 0 <z<1、0≦u≦0.2)。

[0049] Comparative Example 1 Comparative Example 1 was the same as Example 1 except that the sintering conditions in the preparation process of the lithium titanium aluminum phosphate solid electrolyte powder were a sintering temperature of 950° C. and a sintering time of 12 hours.

[0050] Comparative Example 2 In Comparative Example 2, the chemical formula of the LATP material is Li 2.0 Al 0.4 Ti 1.6 Sn 0.6 (P0.8 The same as Example 2 except that the solubility was 0.04).

[0051] Comparative Example 3 Comparative Example 3 was the same as Example 3, except that the particle size of the LATP material was 1200 nm.

[0052] Comparative Example 4 In Comparative Example 4, the chemical formula of the LATP material is Li 1.8 Al 0.5 Ti 1.5 Ge 0.3 (P 0.9 The same as in Example 4 except that the solubility was 0.04).

[0053] Comparative Example 5 In Comparative Example 5, the chemical formula of the LATP material is Li 1.4 Al 0.1 Ti 1.9 Si 0.3 (P 0.9 The same as in Example 5 except that the solubility was 0.04).

[0054] Comparative Example 6 In Comparative Example 6, in the preparation process of lithium titanium aluminum phosphate solid electrolyte powder, titanium pyrophosphate was used instead of ammonium dihydrogen phosphate in the raw materials, and the chemical formula of the LATP material was Li 1.4 Al 0.2 Ti 1.8 Ge 0.2 (P 0.94 The same as in Example 6 except that the solubility was 0.04).

[0055] Comparative Example 7 In Comparative Example 7, the chemical formula of the LATP material is Li 1.4 Al 0.3 Ti 1.7 Sn 0.1 (P 0.97 The procedure was the same as in Example 7, except that the solubility was 0.04%).

[0056] Experimental Example The LATP materials obtained in each of Examples 1 to 7 and Comparative Examples 1 to 7 were subjected to measurements of physical properties, conductivity, modulus of elasticity, dielectric constant, and performance of coin-type batteries, and the measurement methods were as follows.

[0057] 1. Appearance According to the GB / T 16594-2008 standard, the morphology and cross section of the LATP powder, the LATP-coated positive electrode composite, and the LATP-coated separator in Examples 1 to 7 and Comparative Examples 1 to 7 were analyzed using a scanning electron microscope.

[0058] 2. Physical property measurements XRD and XPS measurements were performed on the LATP and LATP-coated cathode composite materials prepared by different processes in Examples 1 to 7 and Comparative Examples 1 to 7, respectively, to observe the changes in physical properties before and after coating. XRD measurement: 1 g of the sample powder to be measured was spread and placed on a glass stage, and a Cu target Kα ray (λ = 0.15406 nm) was used, with a scanning angle of 10 to 90° and a scanning speed of 10° / min. XPS measurement: ESCALAB 250 (vacuum degree 2 × 10 -9 A Thermo Fisher Scientific XPS (X-ray photoelectron spectroscopy) system (<100 mbar) was used. The X-ray source was a monochromated Al Kα source (Mono AlKα), with energy of 1486.6 eV, 15 kV, 150 W, spot size of 500 μm, scan mode: CAE, and lens mode: Large Area XL. Qualitative and quantitative analysis was performed using the Wagner (Al target) library. The survey scan pass energy was 70 eV, and the narrow scan pass energy was 20 eV. Charge correction was performed based on the surface contamination C1s (284.8 eV). XPS measurement requirements: The sample surface must be flat, have good conductivity, and be no larger than 10 mm x 10 mm x 5 mm. Measurement elements included C, Ni, Co, Mn, Li, Ti, P, Al, and O, with the focus on the three elements Ni, Ti, and P.

[0059] 3. Conductivity Measurement AC impedance measurements were performed on LATP materials prepared by different processes. The measurement equipment was a BioLogic electrochemical system, and the EC-Lab software was used. The measurement frequency was 1,000,000 Hz to 0.01 Hz, and the amplitude was 5 mA. Three parallel measurements were performed for each sample. Sample preparation: 0.5 g of dried LATP powder was pressed into a sheet using a 15 mm diameter die at 300 MPa for 1 min. The sheet thickness was 1–2 mm. The sheet was then heat-treated at 850°C for 10 h, cooled to room temperature, and stored in a vacuum-sealed container. The density was >90%. Gold was uniformly coated on both sides of the LATP sheet, and AC impedance spectra were measured using the EC-Lab. A Swagelok-type tube (with a Teflon insulating inner wall) was selected, and both ends of the LATP sheet were connected to stainless steel sheets. A torque wrench pressure of 5 mN was applied. It was calculated according to the formula δ=l / (RS), where l and S are the thickness and surface area of ​​the sheet material, respectively, R is the measured AC impedance value, and δ is the lithium ion conductivity.

[0060] 4. Dielectric Constant Measurement The LATP powder was vacuum dried at 200°C for more than 24 hours, pressed into a sheet using a 15 mm diameter mold at 300 MPa for 1 minute, and the sheet material was made 1-2 mm thick. It was then heat-treated at 850°C for 10 hours, cooled to room temperature, and stored in a vacuum-sealed container. The density was over 90%. Dielectric constant measurement: Gold was coated on both sides of the LATP sheet material. The gold coating had an area S of 50.24 mm. 2 The thickness was 1.5 mm, and the dielectric constant was measured at room temperature using an Agilent 4294A impedance analyzer. The measurement frequency was 40 to 10,000,000 Hz, and 10 MHz points were counted.

[0061] 5. Elastic Modulus Measurement The LATP powder was vacuum dried at 200°C for more than 24 hours, then pressed into a sheet using a 15mm diameter mold at 300MPa for 1 minute. The sheet was then pressed to a thickness of 1-2mm. The sheet was then heat treated at 850°C for 10 hours, cooled to room temperature, and stored in a vacuum-sealed container. The compactness was over 90%. Elastic modulus measurement: The indentation elastic modulus of the LATP sheet sample was measured using a durometer under a constant pressure load of 20mN. E = (1-V s 2 ) / (1 / E r -(1-V i 2 ) / E i ) equation, where E is the indentation elastic modulus and E r is the converted elastic modulus due to indentation contact, and E i is the elastic modulus of the indenter, 1140 GPa, and V i is the Poisson's ratio of the indenter, 0.07, and V s The Poisson's ratio was 0.28, and two surfaces were measured for each sample, 60 points were measured, and 10 samples were selected to perform Gaussian fitting to obtain the elastic modulus of the sample.

[0062] 6. Coin cell battery performance measurement CR2032 coin-type semi-solid-state batteries or Swagelok all-solid-state batteries were assembled and their battery cycling performance was measured. For NCM-Li (or graphite) systems, the capacity retention was calculated at 50 cycles at a voltage of 2.0 to 4.3 V and a current of 0.05 C. For Li-air batteries, measurements were made at a voltage of 2.0 to 4.5 V and a current of 1 C. For Li-S semi-solid-state batteries, measurements were made at a voltage of 1.7 to 3.2 V and a current of 1 C. All-solid-state battery: (1) A 500 μm-thick solid electrolyte layer was prepared by cold-pressing LATP nanopowder at 20 MPa for 1 min. The conductive material Super P, binder, graphite anode, and NCM9055 cathode are placed on both ends of the LATP solid electrolyte layer, and cold-pressed or die-cast at 300 MPa. (2) A certain amount of binder, NMP, etc., is added to prepare the appropriate electrode slurry, which is then coated on both sides of the solid electrolyte (LATP oxide, sulfide, polymer, or combination thereof as described in (4) above) and dried. Alternatively, it can be combined with metallic lithium and lithium alloy anodes (by cold-pressing, thermal evaporation, magnetron sputtering, or vapor deposition) to form a lithium all-solid-state battery. Semi-solid battery: The positive and negative electrode active materials, LATP material, conductive carbon, and binder are uniformly mixed, and an NMP / water-based slurry is prepared. This is then coated on Al or copper foil and vacuum-dried to form the positive and negative electrodes. The above positive and negative electrodes and LATP-coated separators are then combined with the appropriate commercially available electrolyte or polymer to form a semi-solid battery.

[0063] The measurement results of the physical properties, conductivity, elastic modulus, and dielectric constant of the LATP materials in Examples 1 to 7 and Comparative Examples 1 to 7 are shown in Table 1, the performance measurement results of the coin-type batteries are shown in Table 2, and the relationship between the elastic modulus and dielectric constant of the LATP-based inorganic solid electrolyte is shown in Figure 9.

[0064] [Table 1]

[0065] As can be seen from Table 1, the LATP inorganic solid electrolytes of Examples 1 to 7 and Comparative Examples 1 to 7 all had a physical purity of 99%, a lithium ion conductivity of 1E-4 S / cm, an elastic modulus x of 56 GPa to 95 GPa, and a dielectric constant y of 195 to 400. Regarding the composite function F(x, y) = y - 2.79x corresponding to each sample in Examples 1 to 7 and Comparative Examples 1 to 7, Examples 1 to 7 satisfied 50 ≦ F(x, y) ≦ 100, while Comparative Examples 1 to 7 did not satisfy the above functional relationship. As can be seen from Figure 9, all of the data points for each sample in Examples 1 to 7 were between the two straight lines formed by F(x, y), while the theta points for each sample in Comparative Examples 1 to 7 were outside that region.

[0066] [Table 2]

[0067] As can be seen from Table 2 above, Examples 1 to 4 and Comparative Examples 1 to 4 correspond to a ternary lithium coin battery (model number: 2032), Examples 1 to 3 correspond to all-solid-state lithium-ion batteries, and Examples 4 and 7 correspond to semi-solid metal lithium batteries. Examples 5 to 6 and Comparative Examples 5 to 6 correspond to semi-solid batteries, i.e., Li-Air batteries and Li-S batteries, respectively. As shown in Table 2, Examples 1 to 3 and Comparative Examples 1 to 3 have relatively small initial specific capacities and initial coulombic efficiencies. In contrast, Comparative Examples 4 to 7 have smaller initial specific capacities and initial coulombic efficiencies than Examples 4 to 7. This is presumably due to the relatively low lithium ion conductivity of Comparative Examples 4 to 7. After 50 cycles, the discharge specific capacity retention rates of Examples 1 to 7 were all greater than 92%, while the discharge specific capacity retention rates of Comparative Examples 1 to 7 were all less than 90%. The reason for the relatively large differences in the capacity retention rates is that the dielectric constants and elastic moduli of the LATP inorganic solid electrolyte materials of Comparative Examples 1 to 7 do not satisfy the composite function F(x, y) = y - 2.79x and 50 ≦ F(x, y) ≦ 100.

[0068] As mentioned above, LATP (lithium titanium aluminum phosphate, (Li 1+z+3uAl z Ti 2-z M 3u (P 1-u (P 1-u O4)3, M = Ti, Zr, Hf, Si, Ge, Sn, etc., 0 < z < 1, 0 ≤ u ≤ 0.2) The elastic modulus E (denoted as x) and the dielectric constant ε (denoted as y) of the oxide solid electrolyte material constitute a mechanical composite function F(x, y), and it was noticed that both affect the attenuation of the battery capacity. The LATP material with a large dielectric constant (y) corresponds to LATP with a high lithium content (z = 0.5), and due to the relatively low lithium ion conductivity at room temperature, both the capacity and the retention rate were low. The material with a small dielectric constant (y) corresponds to LATP with a low lithium content (z = 0.1), and the lithium ion transport rate was relatively low, and both the capacity and the retention rate were low. The material with a large elastic modulus (x) had a high hardness, poor contact between particles, a relatively large resistance, and low battery capacity and retention rate. The material with a small elastic modulus (x) had a low hardness, good contact between particles, a relatively small resistance, and high battery capacity and retention rate.

[0069] Therefore, a solid lithium battery with high capacity and capacity retention rate has an appropriate dielectric constant and elastic modulus, preferably 49.54 ≤ F(x, y) = y - 2.79x ≤ 100.95. As can be seen from the literature, in order to resist lithium dendrites, it is sufficient for the elastic modulus E of the separator to satisfy E > 5 GPa. The LATP-based material generally has an elastic modulus exceeding 50 GPa. Therefore, in order to enhance the elastic contact between the solid electrolyte particles, the smaller this value, the more preferable. It is not preferable for the dielectric constant to be too large, because if it is too large, the lithium ion conductivity of the LATP material will decrease.

[0070] As shown in Figures 4 and 5, the NCM9055 cathode composite coated with the LATP-3 solid electrolyte in Example 3 exhibited a relatively uniform and dense coating layer, approximately 300 nm thick. The cathode powder maintained a relatively good spherical shape, ensuring good granular contact and relatively low resistance. Figure 10 shows the constant current charge / discharge curves of the Li-LATP@C cathode in Example 3. It can be seen that when the cathode material was coated with LATP, the LATP itself achieved an active capacity of 100-120 mAh / g near 2.5 V, thereby supplementing the cathode with lithium and contributing to the initial battery capacity and initial coulombic efficiency.

[0071] The use of the LATP-3 solid electrolyte, with an elastic modulus E of 65 GPa, is homogeneous with the LATP coating / doping in the positive and negative electrodes, significantly reducing the contact resistance between the solid electrolyte separator and the positive and graphite negative electrodes. Furthermore, a positive electrode composite coated with high-lithium LATP (1 mol of LATP contains 1.8 mol of Li) can supplement lithium in the positive electrode, thereby improving the initial specific capacity and Coulombic efficiency, and achieving a capacity retention rate of 96.04% after 50 cycles at 0.05 C. Example 3 outperforms Examples 1 and 2, primarily due to the relatively high elastic modulus of the solid electrolytes in Examples 1 and 2, and the incomplete coating of the positive electrode material with the solid electrolyte (see Figures 1-3). Example 3 outperforms Comparative Examples 1-3, primarily due to the relatively high elastic modulus of the solid electrolytes in Comparative Examples 1-3, and excessively high or low dielectric constants.

[0072] In Examples 4 to 7, lithium semi-solid-state batteries were assembled using LATP-coated separators. Compared to those using PE separators, they exhibited excellent electrolyte wettability, allowing the amount of electrolyte used to be reduced to approximately two-thirds of the amount typically used, improving safety and gradually becoming all-solid-state batteries. Furthermore, the PTFE binder layer on the surface of the LATP-coated separator improved adhesion between the separator and the positive electrode, significantly reducing contact resistance between the separator and the positive electrode, mitigating electrode expansion during charge and discharge, resisting lithium dendrites, and improving cycle capacity retention.

[0073] In Example 7, the lithium semi-solid battery assembled using a general ternary positive electrode and an LATP-coated separator had a significantly higher capacity retention rate after 50 cycles than that of Comparative Example 7, and the latter had a dielectric constant and elastic modulus outside the ranges required by this invention.

[0074] In Comparative Examples 5 and 6, the inorganic solid electrolytes LATP-5 and LATP-6 had a relatively low elastic modulus, x<65 GPa, and the Li-air batteries and Li-S batteries assembled using them, respectively, did not satisfy the relationship between the dielectric constant y and the elastic modulus x, 49.54≦F(x,y)=y−2.79x≦100.95. As a result, polarization of the porous air positive electrode in the lithium-air battery or shuttle due to polysulfides in the lithium-sulfur battery became severe, and the capacity retention rates of the batteries manufactured using Comparative Examples 5 and 6 were less than 85%.

[0075] Figure 11 shows the XRD diffraction spectrum of the LATP nanomaterial prepared in Example 3, and Figure 12 shows the XRD diffraction spectrum of NCM9055 coated with LATP in Examples 1 to 4. As can be seen from the spectra, LATP is almost pure, and no peaks corresponding to other impurities were observed. After coating NCM9055 with LATP, no peaks corresponding to LATP were observed, which is presumed to be due to the relatively low LATP content (1%).

[0076] Figures 13 to 15 are XPS spectra of the materials coated with NCM9055 by LATP according to Examples 1 to 3, and it can be confirmed that signals corresponding to LATP appear in each of Examples 1 to 3 using XPS. Therefore, a relatively high capacity retention rate was obtained in the semi-solid battery system by combining the LATP-coated cathode and the LATP-coated separator. As described above, for the oxide solid electrolyte material LATP (lithium aluminum titanium phosphate, (Li 1+z+3u Al z Ti 2-z M 3u (P 1-u O4)3, M = Ti, Zr, Hf, Si, Ge, Sn, etc., 0 < z < 1, 0 ≦ u ≦ 0.2), the elastic modulus E (denoted as x) and the dielectric constant ε (denoted as y) constitute a composite function F(x, y) related to mechanics. When 50 ≦ F(x, y) = y - 2.79x ≦ 100 is satisfied, LATP coating or LATP doping is performed in the anode and cathode structures. In this case, the battery has the highest capacity and capacity retention rate (after 50 cycles, the capacity retention rate is over 92%).

[0077] Each of the above examples is only for explaining the technical solution of the present disclosure and does not limit it. Although the present disclosure has been described in detail using each of the above examples, those skilled in the art may modify the technical solutions described in each of the above examples, or perform equivalent substitutions for some or all of their technical features. These modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the scope of the technical solutions of each example of the present disclosure.

[0078] Also, some of the examples here have some features included in other examples, but those skilled in the art should understand that combinations of features of different examples become other examples belonging to the scope of this application. For example, in the claims, the examples to be protected may be arbitrarily combined. The information disclosed in the background art section is only for deepening the understanding of the entire background art of this application and should not be construed as admitting or implicitly suggesting in any form that it is well-known prior art.

[0079] Industrial Applicability The rechargeable high-safety lithium battery according to the present disclosure has a dielectric constant y and an elastic modulus x that satisfy the relational expression 40

Claims

1. 1. A lithium titanium aluminum phosphate electrolyte material, comprising: The mass content of the lithium titanium aluminum phosphate in the lithium titanium aluminum phosphate electrolyte material is 95% to 100%, and the chemical formula of the lithium titanium aluminum phosphate is Li １＋ｚ＋３ｕ Al ｚ Ti ２－ｚ M ３ｕ (P １－ｕ O ４ ) ３ wherein M is one or more selected from Ti, Zr, Hf, Si, Ge, and Sn, z satisfies 0<z<1, and u satisfies 0≦u≦0.2, and the lithium titanium aluminum phosphate has an elastic modulus x of 56 GPa to 95 GPa, a dielectric constant y of 195 to 400, and the dielectric constant y and the elastic modulus x satisfy the relational expression 40<y−2.79x≦120.

1. A lithium titanium aluminum phosphate electrolyte material.

2. The lithium titanium aluminum phosphate has a dielectric constant y and an elastic modulus x that satisfy the relational expression 50≦y−2.79x≦100.

2. The lithium titanium aluminum phosphate electrolyte material according to claim 1.

3. The elastic modulus x of the lithium titanium aluminum phosphate satisfies 60≦x<95.

3. The rechargeable high-safety lithium battery according to claim 1 or 2.

4. A rechargeable high-safety lithium battery comprising a positive electrode, a negative electrode, and an electrolyte located between the positive electrode and the negative electrode, wherein the electrolyte comprises lithium titanium aluminum phosphate, the chemical formula of which is Li １＋ｚ＋３ｕ Al ｚ Ti ２－ｚ M ３ｕ (P １－ｕ O ４ ) ３ M is one or more selected from Ti, Zr, Hf, Si, Ge, and Sn, z satisfies 0<z<1, u satisfies 0≦u≦0.2, and the dielectric constant y and elastic modulus x of the lithium titanium aluminum phosphate satisfy the relational expression 40<y−2.79x≦120. A highly safe rechargeable lithium battery.

5. A rechargeable high-safety lithium battery including a positive electrode, a negative electrode, and an electrolyte located between the positive electrode and the negative electrode, wherein the electrolyte includes lithium titanium aluminum phosphate, the content of the lithium titanium aluminum phosphate in the electrolyte is 95% to 100%, and the chemical formula of the lithium titanium aluminum phosphate is Li １＋ｚ＋３ｕ Al ｚ Ti ２－ｚ M ３ｕ (P １－ｕ O ４ ) ３ wherein M is one or more selected from Ti, Zr, Hf, Si, Ge, and Sn, z satisfies 0<z<1, and u satisfies 0≦u≦0.2, and the lithium titanium aluminum phosphate has an elastic modulus x of 56 GPa to 95 GPa, a dielectric constant y of 195 to 400, and the dielectric constant y and the elastic modulus x satisfy the relational expression 40<y−2.79x≦120; The lithium battery is a solid-state battery and / or a semi-solid-state battery. In the solid-state battery, the lithium titanium aluminum phosphate is cold-pressed to form a sheet to obtain a solid electrolyte. In the semi-solid battery, the lithium titanium aluminum phosphate is applied to a separator. A highly safe rechargeable lithium battery.

6. The lithium titanium aluminum phosphate has a dielectric constant y and an elastic modulus x that satisfy the relational expression 50≦y−2.79x≦100.

6. The rechargeable high-safety lithium battery according to claim 4 or 5.

7. The elastic modulus x of the lithium titanium aluminum phosphate satisfies 60≦x<95.

7. The rechargeable highly safe lithium battery according to claim 4.

8. The positive electrode active material in the positive electrode powder of the positive electrode is coated with the lithium titanium aluminum phosphate, and / or the negative electrode powder of the negative electrode is doped with the lithium titanium aluminum phosphate.

8. The rechargeable highly safe lithium battery according to claim 4.

9. The lithium battery is a lithium ion battery, and the positive electrode powder contains, by mass fraction, 80% to 99% of a positive electrode active material, 0.2% to 20% of a conductive agent, 0.2% to 20% of a binder, and 0% to 20% of an additive.

9. The rechargeable high-safety lithium battery according to claim 8.

10. The lithium battery is a lithium ion battery, and the negative electrode powder contains, by mass fraction, 80% to 99% of a negative electrode active material, 0.2% to 20% of a conductive agent, 0.2% to 20% of a binder, and 0% to 20% of an additive.

10. The rechargeable high-safety lithium battery according to claim 8 or 9.

11. The lithium battery is a lithium-air battery, and the positive electrode powder contains 80% to 99% of a positive electrode active material, 0.5% to 20% of a conductive agent, 0.2% to 20% of a binder, and 0% to 20% of an additive.

9. The rechargeable high-safety lithium battery according to claim 8.

12. The lithium battery is a lithium-sulfur battery, and the positive electrode powder contains 80% to 99% of a positive electrode active material, 0.2% to 20% of a conductive agent, 0.2% to 20% of a binder, and 0% to 20% of an additive.

9. The rechargeable high-safety lithium battery according to claim 8.

13. The positive electrode active material is NCM, NCA, lithium-rich manganese-based material, LFP, LiMO ２ ,S,FeS,FeS ２ , Li ２ S, and porous carbon materials, ２ wherein M is selected from Mn, Co, or Ni.

13. The rechargeable highly safe lithium battery according to claim 8.

14. The negative electrode active material is one or more selected from metallic lithium, lithium alloy, graphite, Si, SiO, SiC, and LTO.

11. The rechargeable high-safety lithium battery according to claim 10.

15. The conductive agent is one or more selected from carbon black, conductive graphite, carbon fiber, carbon nanotube, graphene, carbon aerogel, and conductive carbon nitride.

13. The rechargeable highly safe lithium battery according to claim 9.

16. The binder is one or more selected from the group consisting of polyvinylidene fluoride, polytetrafluoroethylene, carboxymethyl cellulose, styrene butadiene rubber, methyl cellulose, polyacrylic acid, polyacrylate, and polyacrylonitrile.

13. The rechargeable highly safe lithium battery according to claim 9.

17. The additive is one or more selected from oxides, sulfides, halides and polymers.

13. The rechargeable highly safe lithium battery according to claim 9.

18. The preparation process for coating the positive electrode active material with the lithium titanium aluminum phosphate includes the following steps: mixing the positive electrode active material and the additive and dispersing the mixture in absolute ethanol to obtain a positive electrode active material solution; uniformly mixing the lithium titanium aluminum phosphate and the positive electrode active material solution to a powder solid content of 20% to 50%, spray drying, setting the gas inlet temperature to 200 to 300°C and the gas outlet temperature to 100 to 200°C, and then heat treating at 500 to 800°C in an oxygen gas atmosphere for 2 to 24 hours to obtain a positive electrode active material coated with the lithium titanium aluminum phosphate.

18. The rechargeable highly safe lithium battery according to claim 8.

19. The lithium battery includes a solid-state battery and / or a semi-solid-state battery. In the solid-state battery, the lithium titanium aluminum phosphate is cold-pressed to form a sheet to obtain a solid electrolyte. In the semi-solid battery, the lithium titanium aluminum phosphate is applied to a separator.

5. The rechargeable high-safety lithium battery according to claim 4.

20. The manufacturing process of the lithium titanium aluminum phosphate includes any one of dry mix sintering, liquid phase spray sintering, sol-gel sintering, melt quench sintering, sputtering sintering, vapor deposition sintering, electrospinning sintering, and vapor growth / electrochemical growth sintering.

20. The rechargeable highly safe lithium battery according to claim 4.

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