Lithium-ion battery materials, methods for preparing the same, and their use

Abstract

The present disclosure provides a lithium-ion battery material, a method for preparing the same, and its use. The structural formula of the lithium-ion battery material is Li4ZrF 8-2X O X where X satisfies 0 < X ≤ 0.15. The present disclosure can significantly improve the ionic conductivity of the Li4ZrF8 material by performing oxygen doping on the Li4ZrF8 material with a zirconium-containing oxide and performing oxygen doping at the F site. Li4ZrF 8-2X O X When the material is used in a lithium-ion battery, it reacts with water molecules in the electrolyte to generate hydroxyl groups, and then contributes to reducing the moisture in the electrolyte.

Description

[Technical Field]

[0001] This disclosure relates to the technical field of battery materials, and more particularly to lithium-ion battery materials, methods for preparing the same, and their use.

[0002] Cross-reference of related applications This disclosure claims priority based on a Chinese patent application filed with the China Patent Office on June 5, 2023, with application number 202310656029.4 and title "Lithium-ion battery material, method of preparation thereof and use." [Background technology]

[0003] Lithium-ion batteries are currently the most mature and high-performance electrochemical energy storage devices, offering advantages such as high density and low cost, making them ideal energy storage solutions for new energy vehicles, solar power, and wind power. However, with the diversification of application scenarios, demands on the safety, energy density, and lifespan of lithium-ion batteries are increasing. Reducing the amount of electrolyte used and developing solid-state batteries has become a common understanding throughout the industry. However, due to constraints such as current material systems, process maturity, and manufacturing equipment, the industrialization of all-solid-state batteries remains challenging. Under the concept of reducing the amount of electrolyte used in batteries, preparing solid-liquid mixed lithium-ion batteries using solid electrolyte materials with lithium-ion conductivity represents the most promising direction for development.

[0004] Fluoride solid electrolyte materials have a wide electrochemical window and high chemical stability, making them one of the hot spots in current solid electrolyte research. Li4ZrF8 material, as a type of fluoride solid electrolyte, has a theoretically calculated electrochemical window of 1.21–6.38V, making it highly promising for applications in high-voltage systems. The following information was disclosed in the literature (Rakhmatullin A, M Boca, J Mlynarikova, et al. Solid state NMR and XPS of ternary fluorido-zirconates of various coordination modes [J]. Journal of Fluorine Chemistry, 2018, 208): At a temperature of 363K, LiF (0.519g, 20.008mmol) and H2O (20cm³) were used. 3 Stir the mixture, then add ZrF4 (1.675g, 9.999 mmol), boil the reaction mixture for 5 minutes, then let it cool to 363K, and then add 10% HF (90cm²). 3 The solution was slowly added. As the solution cooled, small crystals began to precipitate, and the solution was filtered through filter paper to separate the precursor and obtain the Li4ZrF8 material. When Li4ZrF8 is prepared using the above method, the process is complicated and time-consuming, and the ionic conductivity of the prepared Li4ZrF8 material is relatively low.

[0005] Currently, the main components of the electrolyte used in lithium-ion batteries are lithium salts and organic solvents, both of which readily absorb moisture from the environment. LiPF6, the most commonly used lithium salt, has very high solubility in water. In commercial lithium-ion batteries, the water content of the electrolyte is generally controlled to around 50 ppm. The hydrolysis reaction equation for LiPF6 is LiPF6 + H2O → POF3↑ + HF + LiF↓. Therefore, reducing the water content in the electrolyte is both a focus and a challenge in the research and development of lithium-ion battery electrolytes. [Overview of the project]

[0006] In view of this, an object of the present disclosure is to provide a lithium-ion battery material having relatively high ionic conductivity, a preparation method thereof, and uses. The present disclosure further provides a solid electrolyte material for solid-liquid mixing, Li4ZrF 8-2X O X When the material is used in a lithium-ion battery, it can sufficiently contact the electrolyte solution, contribute to reducing the moisture in the electrolyte solution, and improve the cycle stability of the battery.

[0007] The present disclosure provides a lithium-ion battery material. The structural formula of the lithium-ion battery material is Li4ZrF 8-2X O X where X satisfies 0 < X ≤ 0.15.

[0008] The present disclosure provides a preparation method of a lithium-ion battery material. The preparation method includes mixing a zirconium source, a lithium source, and a fluorine-containing acid solution, reacting and filtering to obtain a precursor, ball milling the precursor and a zirconium-containing oxide in a medium to obtain a slurry, drying and sintering the slurry to obtain a lithium-ion battery material with the general formula Li4ZrF 8-2X O X where X satisfies 0 < X ≤ 0.15.

[0009] In the present disclosure, the zirconium source is zirconium carbonate, and the lithium source is selected from lithium carbonate and / or lithium hydroxide.

[0010] The fluorine-containing acid solution is selected from hydrofluoric acid.

[0011] The zirconium-containing oxide is one or more selected from zirconia, lithium zirconate, and zirconium hydroxide.

[0012] The medium is one or more selected from ethanol, isopropyl alcohol, n-butanol, n-hexane, N-methylpyrrolidone, acetonitrile, dimethylformamide and dimethyl sulfoxide.

[0013] In the present disclosure, the temperature of the sintering is 400°C to 800°C, and the time of the sintering is 12 hours to 24 hours.

[0014] The lithium ion battery material according to the above technical solution or the lithium ion battery material prepared by the preparation method according to the above technical solution is used as a solid electrolyte in a cathode coating material, an electrolyte additive, a cathode plate additive, an anode plate additive or a separator coating material.

[0015] The present disclosure provides a method for coating a cathode material. The coating method includes the steps of using the lithium ion battery material according to the above technical solution as a solid electrolyte, coating the surface of the cathode material with Li4ZrF 8-2X O X of the lithium ion battery material, and then sintering for preparation.

[0016] The temperature of the sintering is 300°C to 600°C, and the time of the sintering is 5 hours to 10 hours.

[0017] The rotation speed of the coating device is 10 rpm to 550 rpm, and the coating time is 1 hour to 3 hours.

[0018] The present disclosure provides a solid electrolyte material for solid-liquid mixing. The solid electrolyte material for solid-liquid mixing includes Li4ZrF 8-2X O X of the lithium ion battery material according to the above technical solution and an electrolyte.

[0019] The electrolyte includes LiPF6.

[0020] The present disclosure provides the use of a solid electrolyte material for solid-liquid mixing. The solid electrolyte material according to the above technical solution is used in energy storage systems of lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, aluminum-ion batteries and fuel cells.

[0021] The present disclosure provides a battery. The battery includes a battery plate and an electrolyte solution, and the battery plate includes an active material and the lithium-ion battery material according to the above technical solution mixed with the active material.

[0022] The electrolyte solution contains LiPF6.

[0023] The present disclosure provides a battery. The battery includes a coated separator and an electrolyte solution.

[0024] The coated separator includes a base film and the lithium-ion battery material according to the above technical solution coated on the surface of the base film.

[0025] The electrolyte solution contains LiPF6.

[0026] The present disclosure provides a lithium-ion battery material. The structural formula of the lithium-ion battery material is Li4ZrF 8-2X O X where X satisfies 0 < X ≤ 0.15. The present disclosure performs oxygen doping on the Li4ZrF8 material with zirconium-containing oxide, and the composition of the material after doping is Li4ZrF 8-2X O X . By performing oxygen doping at the F site, a significant improvement in the ionic conductivity of the Li4ZrF8 material is realized. In addition, the preparation method of the lithium-ion battery material is simple in operation and easy to execute.

[0027] The present disclosure further provides a solid electrolyte material for solid-liquid mixing. Li4ZrF 8-2X O XWhen used in a lithium-ion battery, the material can come into sufficient contact with the electrolyte. There is a trace amount of water (≦50 ppm) in currently commercially available electrolytes. Since the fluorine element has a much higher electronegativity than the hydrogen and oxygen elements, the fluoride bond formed with metal ions is very stable and difficult to cleave. Therefore, fluoride crystals are unlikely to generate free metal ions and fluoride ions on the surface and cannot react with water molecules to produce hydroxyl groups. The present disclosure changes the surface state of the Li4ZrF 8-2X O X material by performing oxygen doping at the F site. When the Li4ZrF 8-2X O X material comes into sufficient contact with the electrolyte, it reacts with the trace amount of water (≦50 ppm) in the electrolyte to generate hydroxyl groups on the surface of a part of the Li4ZrF 8-2X O X material, forms Li4ZrF 8-2X O X ·(OH) y and contributes to removing the moisture in the electrolyte, and can effectively suppress the hydrolysis side reaction of LiPF6.

Brief Description of the Drawings

[0028] [Figure 1] It is the diffraction pattern of the crystal structure of Li4ZrF7.7O0.15 prepared in Example 1 of the present disclosure.

Modes for Carrying Out the Invention

[0029] The present disclosure provides a lithium-ion battery material. The structural formula of the lithium-ion battery material is Li4ZrF 8-2X O X where X satisfies 0 < X ≦ 0.15.

[0030] In the present disclosure, the X is 0.15, 0.05, 0.1, 0.12 or 0.14.

[0031] The present disclosure provides a method for preparing a lithium-ion battery material. The preparation method includes the steps of mixing a zirconium source, a lithium source, and a fluorine-containing acid solution, reacting and filtering to obtain a precursor, ball-milling the precursor and a zirconium-containing oxide in a medium to obtain a slurry, drying and sintering the slurry to obtain a lithium-ion battery material with the general formula Li4ZrF 8-2X O X where X satisfies 0 < X ≤ 0.15.

[0032] The present disclosure performs oxygen doping at the F site and dopes some F sites with oxygen elements. Since the electronegativity of the F element is high and the adsorption force for Li + is strong, the movement of Li + is hindered, and the sites occupied by the F element in the Li4ZrF8 material are relatively numerous. Therefore, by doping an appropriate amount of oxygen elements, the ionic conductivity of the Li4ZrF8 material can be significantly improved. The method according to the present disclosure has low cost, simple operation, easy execution, and is suitable for mass production.

[0033] In the present disclosure, the zirconium source is zirconium carbonate. The lithium source is selected from lithium carbonate and / or lithium hydroxide.

[0034] In the present disclosure, the zirconium-containing oxide is one or more selected from zirconia, lithium zirconate, and zirconium hydroxide. The zirconium-containing oxide supplies O elements, and by doping O elements into some F sites, a significant improvement in the ionic conductivity of the Li4ZrF8 material can be achieved.

[0035] In the present disclosure, the medium is one or more selected from ethanol, isopropyl alcohol, n-butanol, n-hexane, N-methylpyrrolidone, acetonitrile, dimethylformamide, and dimethyl sulfoxide.

[0036] In this disclosure, the reaction time after mixing the zirconium source, the lithium source, and the fluorine-containing acid solution is 4.5 to 5.5 hours, and in specific examples, the reaction time is 5 hours.

[0037] In this disclosure, the fluorine-containing acid solution is hydrofluoric acid. The hydrofluoric acid used is a 40 wt% aqueous solution of hydrogen fluoride. The medium used for ball milling is one or more selected from ethanol, isopropyl alcohol, n-butanol, n-hexane, NMP (N-methylpyrrolidone), acetonitrile (CH3CN), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). Zirconia balls with a diameter of 0.1 mm to 3 mm are used for ball milling. In specific examples, 1 mm zirconia balls or 0.5 mm zirconia balls are used for ball milling. The lithium-ion battery material is in powder form.

[0038] In this disclosure, the sintering temperature is 400°C to 800°C, and the sintering time is 12 to 24 hours. In a specific example, the sintering temperature is 600°C, 800°C, 400°C, or 500°C, and the sintering time is 12 hours.

[0039] This disclosure describes oxygen doping of a Li4ZrF8 material with a zirconium-containing oxide, and the material composition after doping is Li4ZrF 8-2X O X This disclosure relates to a lithium-ion battery material, Li4ZrF, prepared by oxygen doping at the F site. 8-2X O X It reacts with trace amounts of water in the electrolyte to form Li4ZrF 8-2X O X This method generates hydroxyl groups on the surface of the material and significantly improves the ionic conductivity of the Li4ZrF8 material.

[0040] In specific embodiments, X in the lithium-ion battery material is 0.15, 0.05, 0.1, 0.12, or 0.14.

[0041] This disclosure provides a method for coating a positive electrode material. The coating method uses the lithium-ion battery material according to the above-mentioned technical proposal as a solid electrolyte, and the lithium-ion battery material Li4ZrF 8-2X O X The process includes the step of coating the surface of the positive electrode material and then preparing it by sintering.

[0042] The sintering temperature is 300°C to 600°C, and the sintering time is 5 to 10 hours.

[0043] The rotation speed of the covering device is 10 rpm to 550 rpm, and the covering time is 1 hour to 3 hours.

[0044] In this disclosure, the positive electrode material and the lithium-ion battery material Li4ZrF prepared by the preparation method according to the above technical proposal are used. 8-2X O X The mass ratio is 95-105:1. This disclosure shows that after oxygen doping at the F site, the crystal structure still corresponds to the orthorhombic system and the Pnma space group.

[0045] In the positive electrode material, the 3d orbitals of Ni and the 2p orbitals of oxygen overlap in energy bands, so as the applied voltage increases, in the high lithium ion desorption state (high charge state), O 2- It is oxidized, generating peroxides or superoxides, causing deoxygenation of the electrode, transition metal ions forming unstable, highly oxidizing byproducts, and an interfacial phase transition occurs, resulting in Li4ZrF 8-2X O X After coating the ternary cathode material with the material, the surface Li4ZrF 8-2X O X When the material comes into contact with the electrolyte, Li4ZrF 8-2X O X After reacting with water molecules in the electrolyte to form hydroxyl groups on the surface, Li4ZrF 8-2X O X (OH) y This can form a layer that helps reduce moisture in the electrolyte, thereby improving the battery's cycle stability.

[0046] In this disclosure, the positive electrode material is LiNi x Co y M 1-x-y The material is O2, M is Al or Mn, and satisfies 0.8 ≤ x < 1 and 0 ≤ y ≤ 0.2. When M is Al, the above ternary cathode material is abbreviated as NCA, and when M is Mn, the above ternary cathode material is abbreviated as NCM.

[0047] The coating equipment relating to this disclosure includes, but is not limited to, a high-speed mixer or a three-dimensional mixer. In this disclosure, the rotational speed used for the coating is 10 rpm to 550 rpm, and the coating time is 1 hour to 3 hours.

[0048] In this disclosure, a coin-type battery is preferably manufactured using the above-described coated ternary cathode material as the cathode. The coin-type battery comprises a coated ternary cathode material prepared by the preparation method according to the above-described technical proposal and an electrolyte.

[0049] The electrolyte comprises a lithium salt and a mixed solvent. The mixed solvent is a mixture of ethylene carbonate, dimethyl carbonate, and diethyl carbonate.

[0050] In specific examples, LiPF6 is selected as the lithium salt. The mixed solvent is specifically a mixture of ethylene carbonate, dimethyl carbonate, and diethyl carbonate in a volume ratio of 1:1:1.

[0051] This disclosure provides a solid electrolyte material for solid-liquid mixing. The solid electrolyte material for solid-liquid mixing is Li4ZrF, a lithium-ion battery material according to the above-mentioned technical proposal. 8-2X O X It contains electrolyte. The electrolyte contains LiPF6.

[0052] This disclosure provides the use of solid electrolyte materials for solid-liquid mixing. The solid electrolyte materials for solid-liquid mixing according to the above technical proposal are used in energy storage systems of lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, aluminum-ion batteries, and fuel cells.

[0053] This disclosure provides a battery comprising an electrode plate and an electrolyte, wherein the electrode plate comprises an active material and a lithium-ion battery material according to the above-described technical proposal mixed with the active material.

[0054] The electrolyte contains LiPF6.

[0055] In this disclosure, the electrode plate is either a positive electrode plate or a negative electrode plate. When the electrode plate is a positive electrode plate, the active material is a positive electrode active material, and the mass ratio of the positive electrode active material to the lithium-ion battery material is 100:0.95 to 1.05. The mixed solvent in the electrolyte is preferably a mixture of ethylene carbonate, dimethyl carbonate, and diethyl carbonate in a volume ratio of 1:1:1. When the electrode plate is a negative electrode plate, the active material is a negative electrode active material, and the mass ratio of the negative electrode active material to the lithium-ion battery material is 100:0.95 to 1.05. The mixed solvent in the electrolyte is preferably a mixture of ethylene carbonate, dimethyl carbonate, and diethyl carbonate in a volume ratio of 1:1:1.

[0056] In a battery, lithium-ion battery material is mixed with electrode plates to form electrodes. After reacting with water molecules in the electrolyte to generate hydroxyl groups on the surface, it contributes to reducing the amount of water in the electrolyte, thereby improving the battery's cycle stability.

[0057] This disclosure provides a battery comprising a coated separator and an electrolyte.

[0058] The coated separator includes a base film and a lithium-ion battery material according to the above-described technology applied to the surface of the base film.

[0059] The electrolyte contains LiPF6.

[0060] The coated separator contains the lithium-ion battery material according to the above-described technology. This lithium-ion battery material reacts with water molecules in the electrolyte to generate hydroxyl groups on its surface, which contributes to reducing the moisture content in the electrolyte and improving the battery's cycle stability.

[0061] This disclosure describes the application and measurement of materials using the following methods.

[0062] 1. Measurement of ionic conductivity The above Li4ZrF 8-2X O X Take 0.1 to 5 g of material. Using a mold with a diameter of 10 mm to 15 mm, apply a pressure of 5 to 15 MPa in a tabletop powder press and maintain the pressure for 10 to 20 minutes, then release to obtain a thin piece. Place the above thin piece in a sintering furnace and heat it to 300 to 600°C at a heating rate of 1 to 3°C / min, and maintain the temperature for 12 to 20 hours to obtain the ceramic piece necessary for measurement. Lightly polish the surface of the above ceramic piece using 1000 mesh sandpaper moistened with alcohol using the cross-cross method to remove impurities from the surface and ensure that the thickness of each position of the electrolyte is uniform. Measure the thickness L of the sintered piece using calipers, form a gold-deposited blocking electrode using an ion sputtering apparatus, and use the AC impedance method to determine Li4ZrF 8-2X O X Measure the ionic conductivity of the material.

[0063] 2.Li4ZrF 8-2X O X Then apply the separator. The base film is a polyolefin-based separator and includes, but is not limited to, polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), and polypropylene (PP). PE and PP are preferred as the base film.

[0064] The thickness of the base film is 5 to 30 μm, preferably 7 μm, 9 μm, or 12 μm.

[0065] Li4ZrF on both sides of the base film 8-2X O X The material is applied, with a coating thickness of 0.5 to 5 μm, preferably 1 μm, 2 μm, or 3 μm.

[0066] An electrolyte solution was prepared by dissolving 1 M (mol / L) LiPF6 in ethylene carbonate (EC) / dimethyl carbonate (DMC) / diethyl carbonate (EMC) (volume ratio was 1:1:1). The separator, coated on both sides, was placed in the electrolyte solution in a glove box filled with argon gas and immersed at 25°C for 72 hours before being removed. During this process, the concentrations of water and oxygen in the glove box were controlled to less than 0.01 ppm. The moisture content in the electrolyte solution was measured before and after immersion of the separator, and the Li4ZrF 8-2X O X The results of measuring the moisture content of the separator coated with the material before and after immersion are shown in Table 2.

[0067] 3.Li4ZrF 8-2X O X Measure ternary materials (NCM or NCA) coated with a material.

[0068] A 2032 coin-type battery is assembled in a glove box filled with argon gas, and the water and oxygen concentrations in the glove box are controlled to less than 0.01 ppm. A coated ternary material (NCM or NCA) is used as the positive electrode, polypropylene as the separator, foamed nickel as the support structure and conductive material, and graphite as the negative electrode. An electrolyte is prepared by dissolving 1M LiPF6 in ethylene carbonate (EC) / dimethyl carbonate (DMC) / diethyl carbonate (EMC) (volume ratio was 1:1:1), a half-cell is assembled, and the battery is pressurized and sealed using a sealing device. After standing for a certain period of time, the electrochemical performance is measured. The battery measurements are performed under constant temperature conditions of 25°C. Charge / discharge mode: First, the battery is charged at a constant current and constant voltage for 30 minutes, followed by constant current discharge. For the measurement of cycle performance, the battery is first activated by charging and discharging at a low current of 0.1C three times, and then charged and discharged 100 times at a constant current of 0.5C. For measuring rate performance, constant current charging and discharging are performed on the battery at a current of 0.1C within a voltage range of 2.75 to 4.3V.

[0069] 4.Li4ZrF 8-2X O X The materials are mixed into the positive electrode plate.

[0070] Li4ZrF at 1% of the mass of the positive electrode active material 8-2X O X The materials are mixed into a positive electrode plate, a pouch-type battery is prepared using the mixed positive electrode plate, and the capacity retention rate of the pouch-type battery after different cycles is measured.

[0071] 5.Li4ZrF 8-2X O X The materials are mixed into the negative electrode plate.

[0072] Li4ZrF at 1% of the mass of the negative electrode active material 8-2X O X The materials are mixed into a negative electrode plate, a pouch-type battery is prepared using the mixed negative electrode plate, and the capacity retention rate of the pouch-type battery after different cycles is measured.

[0073] To further illustrate this disclosure, the method for preparing lithium-ion battery materials and their use according to this disclosure will be described in detail below using examples. These examples do not limit the scope of protection of this disclosure.

[0074] Example 1 (X=0.15, oxygen element doping was performed using lithium zirconate) 1. Preparation of materials 1. Zirconium carbonate, hydrofluoric acid (40 wt.% hydrogen fluoride aqueous solution), lithium carbonate, lithium zirconate are combined in Li4ZrF 8-2X O X The materials were weighed according to the stoichiometric ratio (X=0.15), where the amount of hydrofluoric acid added was calculated using the actual proportion of hydrogen fluoride. The weighed zirconium carbonate (200.678 g), hydrofluoric acid (385.116 g), and lithium carbonate (144.086 g) were mixed and reacted for 5 hours, after which the precursor was separated by filtration. The precursor and lithium zirconate (7.655 g) were ball-milled for 3 hours in a ball-milling medium, which was isopropyl alcohol, and polishing was performed using zirconia balls with a diameter of 1 mm.

[0075] The slurry after the ball milling process described above is dried, and the dried powder is placed in a sintering furnace and sintered at 800°C for 12 hours to obtain Li4ZrF 7.7 O 0.15 A powder material with (X=0.15) was obtained.

[0076] Figure 1 shows the Li4ZrF prepared in Example 1. 7.7 O 0.15 The diffraction data of the crystal structure is shown. As shown in the figure, after oxygen doping at the F site, the crystal structure still corresponds to the orthorhombic system and the Pnma space group.

[0077] II. Application and Measurement of Materials 1. Measurement of ionic conductivity The above Li4ZrF 7.7 O 0.151 g of the material was taken. Using a mold with a diameter of 10 mm, a pressure of 10 MPa was applied in a tabletop powder press, and after maintaining the pressure for 10 minutes, demolding was performed to obtain a thin sheet. The above thin sheet was placed in a sintering furnace, heated to 300 °C at a heating rate of 1 °C per minute, and kept warm for 12 hours, thereby obtaining a ceramic piece necessary for measurement. The surface of the above ceramic piece was lightly polished by the cross intersection method using 1000-mesh sandpaper moistened with alcohol to remove impurities on its surface and ensure that the thickness at each position of the electrolyte was uniform. The thickness L of the sintered piece was measured using a vernier caliper, a gold vapor deposition blocking electrode was formed using an ion sputtering device, and the ionic conductivity of Li4ZrF 7.7 O 0.15 of the material was measured, and the measurement data refer to the ionic conductivity measurement data in Table 1.

[0078] 2. The separator was coated with Li4ZrF 7.7 O 0.15 .

[0079] PE was selected as the base film, and the thickness of the base film was 5 μm. The Li4ZrF 7.7 O 0.15 material was coated on both sides of the base film, and the coating thickness was 1 μm. An electrolyte of 1 M LiPF6 in ethylene carbonate (EC) / dimethyl carbonate (DMC) / diethyl carbonate (EMC) (with a volume ratio of 1:1:1) was prepared. In a glove box filled with argon gas, the above separator coated on both sides was placed in the electrolyte, immersed at 25 °C for 72 hours, and then the separator was taken out. In this process, the concentrations of water and oxygen in the glove box were controlled to be less than 0.01 ppm. The moisture values in the electrolyte before and after immersing the separator were measured respectively, and the measurement results were recorded in Table 2.

[0080] 3. The ternary material (NCM or NCA) coated with the Li4ZrF 7.7 O 0.15 material was measured.

[0081] Li4ZrF7.7 O 0.15 The powder material and the ternary cathode material NCM811 were weighed at a mass ratio of 1:100, that is, Li4ZrF 7.7 O 0.15 10 g of the powder material and 1000 g of the NCM811 material were weighed. The materials were put into a coating device with a rotation speed of 200 r / min, taken out after 1 hour, put into a sintering furnace, and kept at 600 °C for 10 hours.

[0082] A 2032 coin-type battery was assembled in a glove box filled with argon gas, and the concentrations of water and oxygen in the glove box were controlled to be less than 0.01 ppm. The coated ternary material NCM811 was used as the cathode, polypropylene PE was used as the separator, foamed nickel was used as the support structure and conductive material, and graphite was used as the anode. 1 M LiPF6 was dissolved in ethylene carbonate (EC) / dimethyl carbonate (DMC) / diethyl carbonate (EMC) (the volume ratio was 1:1:1) to prepare an electrolyte, a half-cell was assembled, and the battery was pressure-sealed using a sealing device. After standing for a certain period of time, the electrochemical performance was measured. The measurement of the battery was carried out under a constant temperature condition of 25 °C. Charge-discharge mode: First, charge at a constant current and then at a constant voltage for 30 minutes, and discharge at a constant current. For the measurement of cycle performance, first, the battery was charged and discharged at a small current of 0.1C for 3 times for activation, and then charged and discharged at a constant current of 0.5C for 100 times. For the measurement of rate performance, the battery was subjected to constant current charge and discharge at a current of 0.1C within a voltage range of 2.75 - 4.3V, respectively. Refer to the data in Table 3 for the measurement results.

[0083] 4.Li4ZrF 7.7 O 0.15 The material was mixed into the positive electrode plate.

[0084] 1% of the mass of the positive electrode active material (NCM) of Li4ZrF 7.7 O 0.15A pouch-type battery was prepared using a ternary positive electrode plate mixed with the materials, a graphite negative electrode plate, a polyolefin separator, and an electrolyte prepared by dissolving 1 M LiPF6 in ethylene carbonate (EC) / dimethyl carbonate (DMC) / diethyl carbonate (EMC) (volume ratio 1:1:1). The cycle performance and capacity retention rate of the pouch-type battery were measured at a constant temperature of 25°C. The voltage range was 2.75 to 4.2 V, and the charge / discharge current was 1.0 C / 1.0 C. The measurement data is recorded in Table 4.

[0085] 5.Li4ZrF 7.7 O 0.15 The material was mixed into the negative electrode plate.

[0086] Li4ZrF at 1% of the mass of the graphite anode active material 7.7 O 0.15 A pouch-type battery was prepared by mixing the material with a graphite negative electrode plate, and using the above-mentioned mixed graphite negative electrode plate, a positive electrode plate, a polyolefin-based separator, and an electrolyte prepared by dissolving 1M LiPF6 in ethylene carbonate (EC) / dimethyl carbonate (DMC) / diethyl carbonate (EMC) (volume ratio was 1:1:1). The cycle performance and capacity retention rate of the pouch-type battery were measured at a constant temperature of 25°C. The voltage range was 2.75~4.2V, and the charge / discharge current was 1.0C / 1.0C. The measurement data is recorded in Table 5.

[0087] Example 2 (X=0.05, oxygen element doping was performed using zirconia) 1. Preparation of materials Zirconium carbonate, hydrofluoric acid (40 wt.% hydrogen fluoride aqueous solution), lithium carbonate, zirconia are converted to Li4ZrF 8-2X O XThe materials were weighed according to the stoichiometric ratio (X=0.05), where the amount of hydrofluoric acid added was calculated based on the actual proportion of hydrogen fluoride. The weighed zirconium carbonate (205.959 g), hydrofluoric acid (395.119 g), and lithium carbonate (147.78 g) were mixed and reacted for 5 hours, after which the precursor was separated by filtration. The precursor and 3.081 g of zirconia were ball-milled for 3 hours in a ball-milling medium, which was ethanol, and polishing was performed using zirconia balls with a diameter of 1 mm.

[0088] The slurry after the ball milling process described above is dried, and the dried powder is placed in a sintering furnace and sintered at 600°C for 12 hours to obtain Li4ZrF 7.9 O 0.05 A powder material with (X=0.05) was obtained.

[0089] II. Application and Measurement of Materials The measurements of ionic conductivity, separator coating, positive electrode plate mixture, and negative electrode plate mixture were the same as in Example 1.

[0090] When coating with a ternary cathode material, Li4ZrF 7.9 O 0.05 The powder material and the ternary cathode material NCM811 were weighed in a weight ratio of 1:95, i.e., Li4ZrF 7.9 O 0.05 10 g of powder material and 950 g of NCM811 material were weighed. The materials were placed in a coating device and rotated at a speed of 200 r / min. After 1 hour, they were removed and placed in a sintering furnace and kept at 600°C for 10 hours. The assembly of the coin cell and the measurement of its electrical performance were the same as in Example 1.

[0091] Example 3 (X=0.1, oxygen element doping was performed using zirconia) 1. Preparation of materials Zirconium carbonate, hydrofluoric acid (40 wt.% hydrogen fluoride aqueous solution), lithium carbonate, zirconia are converted to Li4ZrF 8-2X O XThe materials were weighed according to the stoichiometric ratio (X=0.1), where the amount of hydrofluoric acid added was calculated using the actual proportion of hydrogen fluoride. The weighed zirconium carbonate (200.678 g), hydrofluoric acid (390.117 g), and lithium carbonate (147.78 g) were mixed and reacted for 5 hours, after which the precursor was separated by filtration. The precursor and 6.161 g of zirconia were ball-milled for 4 hours in a ball-milling medium, where n-butanol was used as the ball-milling medium, and zirconia balls with a diameter of 0.5 mm were used for polishing.

[0092] The slurry after the ball milling process described above is dried, and the dried powder is placed in a sintering furnace and sintered at 400°C for 12 hours to obtain Li4ZrF 7.8 O 0.1 A powder material with (X=0.1) was obtained.

[0093] II. Application and Measurement of Materials The measurements of ionic conductivity, separator coating, positive electrode plate mixture, and negative electrode plate mixture were the same as in Example 1.

[0094] Li4ZrF 7.8 O 0.1 The powder material and the ternary cathode material NCM811 were weighed in a weight ratio of 1:100, i.e., Li4ZrF 7.8 O 0.1 10 g of powder material and 1000 g of NCM811 material were weighed. The materials were placed in a coating device and rotated at a speed of 200 r / min. After 1 hour, they were removed and placed in a sintering furnace and kept at 600°C for 10 hours. The assembly of the coin-type battery and the measurement of its electrical performance were the same as in Example 1.

[0095] Example 4 (X=0.12, oxygen element doping was performed using zirconia) 1. Preparation of materials Zirconium carbonate, hydrofluoric acid (40 wt.% hydrogen fluoride aqueous solution), lithium carbonate, zirconia are converted to Li4ZrF 8-2X O XThe materials were weighed according to the stoichiometric ratio (X=0.12), where the amount of hydrofluoric acid added was calculated using the actual proportion of hydrogen fluoride. 198.566 g of zirconium carbonate, 388.116 g of hydrofluoric acid, and 147.78 g of lithium carbonate were mixed and reacted for 5 hours, after which the precursor was separated by filtration. The precursor and 7.393 g of zirconia were ball-milled for 4 hours in a ball-milling medium, which was ethanol, and polishing was performed using zirconia balls with a diameter of 1 mm.

[0096] The slurry after the ball milling process described above is dried, and the dried powder is placed in a sintering furnace and sintered at 800°C for 12 hours to obtain Li4ZrF 7.8 O 0.1 A powder material with (X=0.1) was obtained.

[0097] II. Application and Measurement of Materials The measurements of ionic conductivity, separator coating, positive electrode plate mixture, and negative electrode plate mixture were the same as in Example 1.

[0098] Li4ZrF 7.8 O 0.1 The powder material and the ternary cathode material NCM811 were weighed in a weight ratio of 1:105, i.e., Li4ZrF 7.8 O 0.1 10 g of powder material and 1050 g of NCM811 material were weighed. The materials were placed in a coating device and rotated at a speed of 200 r / min. After 1 hour, they were removed and placed in a sintering furnace and kept at 600°C for 10 hours. The assembly of the coin cell and the measurement of its electrical performance were the same as in Example 1.

[0099] Example 5 (X=0.14, doping with oxygen element using zirconium hydroxide) 1. Preparation of materials Zirconium carbonate, hydrofluoric acid (40 wt.% hydrogen fluoride aqueous solution), lithium carbonate, zirconium hydroxide are combined in Li4ZrF 8-2X O XThe materials were weighed according to the stoichiometric ratio (X=0.1), where the amount of hydrofluoric acid added was calculated based on the actual proportion of hydrogen fluoride. 196.453 g of zirconium carbonate, 386.116 g of hydrofluoric acid, and 95.792 g of lithium hydroxide were mixed and reacted for 5 hours, after which the precursor was separated by filtration. The precursor and 11.148 g of zirconium hydroxide were ball-milled for 4 hours in a ball-milling medium, which was ethanol, and polishing was performed using zirconia balls with a diameter of 1 mm.

[0100] The slurry after the ball milling process described above is dried, and the dried powder is placed in a sintering furnace and sintered at 500°C for 12 hours to obtain Li4ZrF 7.72 O 0.14 A powder material with (X=0.14) was obtained.

[0101] II. Application and Measurement of Materials The measurements of ionic conductivity, separator coating, positive electrode plate mixture, and negative electrode plate mixture were the same as in Example 1.

[0102] Li4ZrF 7.72 O 0.14 The powder material and the ternary cathode material NCA were weighed in a weight ratio of 1:100, i.e., Li4ZrF 7.72 O 0.14 10 g of powder material and 1000 g of NCA material were weighed. The materials were placed in a coating device and rotated at a speed of 200 r / min. After 1 hour, they were removed and placed in a sintering furnace and kept at 600°C for 10 hours. The assembly of the coin cell and measurement of its electrical performance were the same as in Example 1.

[0103] Comparative Example 1 1. Preparation of materials Zirconium carbonate, hydrofluoric acid (40 wt.% hydrogen fluoride aqueous solution), lithium carbonate are used to form Li4ZrF 8-2X O XThe materials were weighed according to the stoichiometric ratio at (X=0), where the amount of hydrofluoric acid added was calculated using the actual proportion of hydrogen fluoride. The weighed zirconium carbonate (211.24 g), hydrofluoric acid (400.12 g), and lithium carbonate (147.78 g) were mixed and reacted for 5 hours. After filtration, the precursor was separated to obtain Li4ZrF8.

[0104] II. Application and Measurement of Materials The measurements of ionic conductivity, separator coating, positive electrode plate mixture, and negative electrode plate mixture were the same as in Example 1.

[0105] Li4ZrF8 powder material and ternary cathode material NCA were weighed in a weight ratio of 1:100, i.e., 10 g of Li4ZrF8 powder material and 1000 g of NCA material were weighed. The materials were placed in a coating apparatus and rotated at a speed of 200 r / min. After 1 hour, they were removed and placed in a sintering furnace and kept at 400°C for 10 hours. The assembly of the coin cell and measurement of its electrical performance were the same as in Example 1.

[0106] The ionic conductivity measurement data for the examples and comparative examples are shown in Table 1. Li4ZrF 8-2X O X The moisture content measurements of the separator coated with the material before and after immersion are shown in Table 2. The electrical performance measurement data of the coated positive electrode is shown in Table 3. Li4ZrF 8-2X O X The measurement results for pouch-type batteries assembled using positive electrode plates coated with the material are shown in Table 4. Li4ZrF 8-2X O X A pouch-type battery assembled using a negative electrode plate coated with the material is shown in Table 5.

[0107] [Table 1]

[0108] Li4ZrF, a lithium-ion battery material prepared in Examples 1-5 of this disclosure. 8-2X O X It reacts with trace amounts of water in the electrolyte to form Li4ZrF8-2X O X Hydroxyl groups were generated on the surface of the material.

[0109] [Table 2]

[0110] [Table 3]

[0111] [Table 4]

[0112] [Table 5]

[0113] As can be seen from the above examples, the present disclosure provides a lithium-ion battery material. The structural formula of the lithium-ion battery material is Li4ZrF 8-2X O X where X satisfies 0 < X ≤ 0.15. The present disclosure performs oxygen doping on the Li4ZrF8 material with a zirconium-containing oxide, and the material composition after doping is Li4ZrF 8-2X O X By performing oxygen doping at the F site, a significant improvement in the ionic conductivity of the Li4ZrF8 material was achieved.

[0114] The present disclosure further provides a solid electrolyte material for solid-liquid mixing. Li4ZrF 8-2X O XWhen used in lithium-ion batteries, the material can come into sufficient contact with the electrolyte. Currently, commercially available electrolytes contain trace amounts of water (≤50 ppm). Because fluorine has a much higher electronegativity than hydrogen and oxygen, the fluoride bonds formed with metal ions are very stable and difficult to cleave. For this reason, fluoride crystals do not easily generate free metal ions and fluoride ions on their surface and cannot react with water molecules to produce hydroxyl groups. This disclosure relates to the formation of Li4ZrF by oxygen doping at the F site. 8-2X O X The surface condition of the material was changed. Li4ZrF 8-2X O X When the material comes into contact with the electrolyte, it can react with trace amounts of water in the electrolyte, and some of the water can react with Li4ZrF 8-2X O X Bonds with the surface of the material and Li4ZrF 8-2X O X · (OH) y This generates a substance that removes some of the water from the electrolyte and effectively suppresses the hydrolysis side reaction of LiPF6.

[0115] According to the experimental results, Li4ZrF 8-2X O X The ionic conductivity of the material is 2.1 × 10⁻⁶ -4 ~4.3 × 10 -4 It was S / m. Li4ZrF 8-2X O X After immersing the material-coated separator in the electrolyte, the moisture content of the electrolyte decreased from 43-48 ppm to 4-7 ppm. The coated ternary cathode had a capacity retention rate of 92-96% after 50 cycles at 0.5C and 91-94% after 100 cycles at 0.5C. Li4ZrF 8-2X O X Positive electrodes prepared using the material-mixed positive electrode active material NCM showed a capacity retention rate of 97.58-97.71% after 100 cycles and 89.31-89.97% after 200 cycles at a voltage of 2.75-4.2V and a charge / discharge current of 1.0C / 1.0C. (Li4ZrF) 8-2X OX The negative electrode plate prepared using the material mixed negative electrode active material had a capacity retention rate of 97.34 - 97.74% after 100 cycles and 89.35 - 89.67% after 200 cycles at a voltage of 2.75 - 4.2V and a charge-discharge current of 1.0C / 1.0C.

[0116] The above are only preferred embodiments of the present disclosure. Those skilled in the art can make some improvements and enhancements on the premise of not departing from the principles of the present disclosure, and these improvements and enhancements also belong to the protection scope of the present disclosure. Industrial Applicability

[0117] The present disclosure provides a lithium-ion battery material. The structural formula of the lithium-ion battery material is Li4ZrF 8-2X O X where X satisfies 0 < X ≤ 0.15. The present disclosure performs oxygen doping on the Li4ZrF8 material with zirconium-containing oxide, and the composition of the doped material is Li4ZrF 8-2X O X By performing oxygen doping at the F site, a significant improvement in the ionic conductivity of the Li4ZrF8 material can be achieved. In addition, the preparation method of the lithium-ion battery material is simple in operation and easy to execute.

[0118] The present disclosure further provides a solid electrolyte material for solid-liquid mixing. The Li4ZrF 8-2X O X material can come into sufficient contact with the electrolyte when used in a lithium-ion battery. There is a trace amount of moisture (≤50 ppm) in currently commercially available electrolytes. Since the fluorine element has a much higher electronegativity than the hydrogen and oxygen elements, the fluoride bond formed with metal ions is very stable and difficult to cleave. Therefore, fluoride crystals are unlikely to generate free metal ions and fluorine ions on the surface and cannot react with water molecules to generate hydroxyl groups. The present disclosure changes the surface state of the Li4ZrF 8-2X O X material by performing oxygen doping at the F site. The Li4ZrF 8-2X OX When the material comes into sufficient contact with the electrolyte, it reacts with trace amounts of water (≤50 ppm) in the electrolyte to form some Li4ZrF 8-2X O X Hydroxyl groups are generated on the surface of the material, and Li4ZrF 8-2X O X (OH) y This forms a layer that contributes to removing moisture from the electrolyte, effectively suppressing the hydrolysis side reaction of LiPF6.

Claims

1. Lithium-ion battery material, The structural formula of the lithium-ion battery material is Li ４ ZrF ８－２Ｘ O Ｘ And X satisfies 0 < X ​​≤ 0.

15. A lithium-ion battery material characterized by the following features.

2. A method for preparing a lithium-ion battery material according to claim 1, The process involves mixing a zirconium source, a lithium source, and a fluorine-containing acid solution, reacting them, and filtering the mixture to obtain a precursor. The steps include ball milling the aforementioned precursor and zirconium-containing oxide in a medium to obtain a slurry, The slurry is dried and sintered, and the general formula is Li ４ ZrF ８－２Ｘ O Ｘ The steps include obtaining a lithium-ion battery material, Here, X satisfies 0 < X ​​≤ 0.

15. A method for preparing lithium-ion battery materials, characterized by the following features.

3. The zirconium source is zirconium carbonate, and the lithium source is selected from lithium carbonate and / or lithium hydroxide. The preparation method according to feature 2.

4. The fluorine-containing acid solution is selected from hydrofluoric acid. The preparation method according to feature 2.

5. The zirconium-containing oxide is one or more selected from zirconia, lithium zirconate, and zirconium hydroxide. The preparation method according to feature 2.

6. The aforementioned medium is one or more selected from ethanol, isopropyl alcohol, n-butanol, n-hexane, N-methylpyrrolidone, acetonitrile, dimethylformamide, and dimethyl sulfoxide. The preparation method according to feature 2.

7. The sintering temperature is 400°C to 800°C, and the sintering time is 12 to 24 hours. The preparation method according to feature 2.

8. The lithium-ion battery material described in claim 1 or the lithium-ion battery material prepared by the preparation method described in any one of claims 2 to 7 is used as a solid electrolyte in a positive electrode coating material, electrolyte additive, positive electrode plate additive, negative electrode plate additive, or separator coating material. Use of lithium-ion battery materials.

9. Using the lithium-ion battery material according to claim 1 as a solid electrolyte, after coating the surface of the positive electrode material with Li ４ ZrF ８－２Ｘ O Ｘ and including the step of sintering for preparation A method for coating a positive electrode material, characterized by the features described above.

10. The sintering temperature is 300°C to 600°C, and the sintering time is 5 to 10 hours. The method for coating a positive electrode material according to feature 9.

11. The rotation speed of the coating equipment is 10 rpm to 550 rpm, and the coating time is 1 hour to 3 hours. The method for coating a positive electrode material according to feature 9.

12. Li of the lithium-ion battery material according to claim 1 ４ ZrF ８－２Ｘ O Ｘ and an electrolyte A solid electrolyte material for solid-liquid mixing, characterized by the following features.

13. The electrolyte is LiPF ６ including The method for coating a positive electrode material according to feature 12.

14. The solid electrolyte material for solid-liquid mixing described in claim 7 is used in the energy storage systems of lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, aluminum-ion batteries, and fuel cells. The use of a solid electrolyte material for solid-liquid mixing, characterized by the following:

15. The battery comprises an electrode plate and an electrolyte, wherein the electrode plate comprises an active material and a lithium-ion battery material according to claim 1 or a lithium-ion battery material prepared by the preparation method according to any one of claims 2 to 7, which is mixed with the active material. A battery characterized by the following features.

16. The electrolyte is LiPF ６ including The battery according to feature 15.

17. It comprises a coating separator and an electrolyte solution. The coated separator includes a base film and a lithium-ion battery material according to claim 1 or a lithium-ion battery material prepared by the preparation method according to any one of claims 2 to 7, which is coated on the surface of the base film. A battery characterized by the following features.

18. The electrolyte is LiPF ６ including The battery according to feature 17.

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