阅读说明：本技术 一种无机氯化物固态电解质材料、其制备方法及其应用 (Inorganic chloride solid electrolyte material, preparation method and application thereof ) 是由 马骋 王凯 于 2020-12-22 设计创作，主要内容包括：本发明提供了无机氯化物固态电解质材料,其化学式为Li-xZr-yCl-(x+4y),其中1≤x≤3,0.5≤y≤1。除了Li和Cl这两种存在于所有氯化物固态电解质中的元素以外,该材料仅含有Zr元素,而Zr在地壳中的丰度远大于组成其它氯化物固态电解质的In、Sc、Y、Tb-Lu等元素,相应的,作为原料ZrCl-4的价格比其它氯化物固态电解质的原料低若干个数量级；进一步的,无机氯化物固态电解质材料在5％湿度的气氛中稳定,这种优异的耐湿性,加上原材料的低成本,消除了无机氯化物固态电解质工业应用的两大障碍,进一步推动全固态电池的大规模工业应用进程。(The invention provides an inorganic chloride solid electrolyte material with a chemical formula of Li x Zr y Cl x+4y Wherein x is more than or equal to 1 and less than or equal to 3, and y is more than or equal to 0.5 and less than or equal to 1. Except for Li and Cl which are two elements existing In all chloride solid-state electrolytes, the material only contains Zr, and the abundance of Zr In the earth crust is far larger than that of In, Sc, Y, Tb-Lu and other elements forming other chloride solid-state electrolytes, and accordingly ZrCl is used as a raw material 4 The price of the electrolyte is several orders of magnitude lower than that of other raw materials of chloride solid electrolytes; further, the inorganic chloride solid electrolyte material is stable in an atmosphere of 5% humidity, the excellent moisture resistance, and the low cost of raw materials eliminate two obstacles of industrial application of the inorganic chloride solid electrolyte, and further promote the large scale of the all-solid-state batteryAnd (5) modeling industrial application process.)

1. An inorganic chloride solid electrolyte material as shown in formula (I),

Li_xZr_yCl_x+4y (Ⅰ)；

wherein x is more than or equal to 1 and less than or equal to 3, and y is more than or equal to 0.5 and less than or equal to 1.

2. The inorganic chloride solid state electrolyte material of claim 1, wherein the inorganic chloride solid state electrolyte material has an ionic conductivity of greater than 1.0 x 10^-4S/cm。

3. The inorganic chloride solid state electrolyte material of claim 1, wherein 1.5. ltoreq. x.ltoreq.2.5, 0.75. ltoreq. y.ltoreq.0.9.

4. The inorganic chloride solid state electrolyte material according to claim 1, characterized in that the inorganic chloride solid state electrolyte material is LiZrCl₅、Li_1.5ZrCl_5.5、Li₂ZrCl₆、Li_2.5ZrCl_6.5、Li₃ZrCl₇Or Li₃Zr_0.75Cl₆。

5. The method of producing an inorganic chloride solid state electrolyte material of claim 1, comprising:

LiCl and ZrCl are added according to stoichiometric ratio₄And (5) ball milling and mixing.

6. The preparation method of the high-speed ball mill is characterized in that the ball-milling mixing ball-material ratio is (5-20): 1, the rotation speed of the ball mill is 200-1000 r/min, and the ball milling time is 12-48 h.

7. The method of claim 5, wherein the mixing further comprises drying and pressing.

8. The method of claim 5, wherein the drying is at 5% humidity N₂The drying is carried out in a vacuum environment, and the drying time is 12-36 hours; the pressing pressure is 300-500 MPa.

9. A lithium ion battery, which comprises a positive electrode, a negative electrode and an electrolyte, wherein the electrolyte is the inorganic chloride solid electrolyte material of any one of claims 1 to 4 or the inorganic chloride solid electrolyte material prepared by the preparation method of any one of claims 5 to 8.

Technical Field

The invention relates to the technical field of solid electrolyte materials of lithium batteries, in particular to an inorganic chloride solid electrolyte material, a preparation method and application thereof

Background

The inorganic all-solid-state lithium battery has higher safety due to the adoption of the non-flammable electrolyte material, and is an important development direction of the next generation lithium ion battery, especially a power battery. In recent years, chloride super-ionic conductors have been proposed as a new promising solid electrolyte; it has high conductivity and easy deformability like sulfide, but is not influenced by oxidation stability of sulfidePoor in the sense of disturbance. However, the reported chloride solid-state electrolytes with high ionic conductivity are composed of elements with very low abundance In the earth's crust (specifically including Sc, In, Y, Tb-Lu), resulting In high raw material cost for these systems. Such as: even the cheapest raw material (YCl)₃) Is also compared with P₂S₅(Li₇P₃S₁₁Raw material of (d) is about 20 times more expensive. Such expensive raw materials represent a great obstacle to large-scale industrial applications.

Another reason that hinders the large-scale industrial application of inorganic chloride solid electrolytes is their humidity instability. Except for Li₃InCl₆The solid electrolyte can be removed of water by heat treatment after water absorption to recover the original performance, and the chloride solid electrolyte consisting of Sc, In, Y and Tb-Lu is unstable In moisture and cannot be recovered by post-treatment. Such as: for Li₃YCl₆Solid electrolyte, even when exposed to 1% humidity, rapidly absorbs water and hydrolyzes.

Disclosure of Invention

The technical problem solved by the invention is to provide an inorganic chloride solid electrolyte material which has ultralow cost and high moisture resistance.

In view of the above, the present application provides an inorganic chloride solid electrolyte material represented by formula (i),

Li_xZr_yCl_x+4y (Ⅰ)；

wherein x is more than or equal to 1 and less than or equal to 3, and y is more than or equal to 0.5 and less than or equal to 1.

Preferably, the inorganic chloride solid state electrolyte material has an ionic conductivity of more than 1.0 x 10^-4S/cm。

Preferably, x is 1.5-2.5, and y is 0.75-0.9.

Preferably, the inorganic chloride solid electrolyte material is LiZrCl₅、Li_1.5ZrCl_5.5、Li₂ZrCl₆、Li_2.5ZrCl_6.5、Li₃ZrCl₇Or Li₃Zr_0.75Cl₆。

The application also provides a preparation method of the inorganic chloride solid electrolyte material, which comprises the following steps:

LiCl and ZrCl are added according to stoichiometric ratio₄And (5) ball milling and mixing.

Preferably, the ball-milling mixing ball-material ratio is (5-20): 1, the ball-milling rotation speed is 200-1000 r/min, and the ball-milling time is 12-48 h.

Preferably, the mixing is followed by drying and pressing.

Preferably, the drying is at 5% humidity N₂The drying is carried out in a vacuum environment, and the drying time is 12-36 hours; the pressing pressure is 300-500 MPa.

The application also provides a lithium ion battery, which comprises a positive electrode, a negative electrode and an electrolyte, wherein the electrolyte is the inorganic chloride solid electrolyte material or the inorganic chloride solid electrolyte material prepared by the preparation method.

The present application provides a catalyst such as Li_xZr_yCl_x+4yThe inorganic chloride solid dielectric material has an ionic conductivity of 1.0 × 10^-4S/cm, is insensitive to air, and cannot absorb water to deteriorate under the humidity of 5 percent; further, ZrCl as a raw material of the present application₄The price of the inorganic chloride solid electrolyte material is lower than that of chlorides corresponding to In, Sc, Y and Tb-Lu by a plurality of orders of magnitude, and the cost of the inorganic chloride solid electrolyte material is obviously reduced.

Drawings

FIG. 1 shows Li synthesized in example 1₂ZrCl₆An X-ray diffraction pattern of the solid electrolyte before and after 24h exposure at 5% humidity;

FIG. 2 shows Li synthesized in example 1₂ZrCl₆Ion conductivity change curve before and after the solid electrolyte is exposed for 24 hours under 5% humidity;

FIG. 3 shows LiZrCl synthesized in example 2₅An X-ray diffraction pattern of the solid electrolyte before and after 24h exposure at 5% humidity;

FIG. 4 shows LiZrCl synthesized in example 2₅Ion conductance of solid electrolyte before and after 24h exposure at 5% humidityA rate change curve;

FIG. 5 shows Li synthesized in example 3_1.5ZrCl_5.5An X-ray diffraction pattern of the solid electrolyte before and after 24h exposure at 5% humidity;

FIG. 6 shows Li synthesized in example 3_1.5ZrCl_5.5Ion conductivity change curve before and after the solid electrolyte is exposed for 24 hours under 5% humidity;

FIG. 7 shows Li synthesized in example 4_2.5ZrCl_6.5An X-ray diffraction pattern of the solid electrolyte before and after 24h exposure at 5% humidity;

FIG. 8 shows Li synthesized in example 4_2.5ZrCl_6.5Ion conductivity change curve before and after the solid electrolyte is exposed for 24 hours under 5% humidity;

FIG. 9 shows Li synthesized in example 5₃ZrCl₇An X-ray diffraction pattern of the solid electrolyte before and after 24h exposure at 5% humidity;

FIG. 10 shows Li synthesized in example 5₃ZrCl₇Ion conductivity change curve before and after the solid electrolyte is exposed for 24 hours under 5% humidity;

FIG. 11 shows Li synthesized in example 6₃Zr_0.75Cl₆An X-ray diffraction pattern of the solid electrolyte before and after 24h exposure at 5% humidity;

FIG. 12 shows Li synthesized in example 6₃Zr_0.75Cl₆Ion conductivity change curve before and after exposure of solid electrolyte to 5% humidity for 24 h.

Detailed Description

For a further understanding of the invention, reference will now be made to the preferred embodiments of the invention by way of example, and it is to be understood that the description is intended to further illustrate features and advantages of the invention, and not to limit the scope of the claims.

In view of the problems of high cost and unstable humidity of the prior art inorganic chloride solid-state electrolytes, the present application provides an inorganic solid-state electrolyte material containing only Zr element in addition to Li and Cl, which are two elements present in all chloride solid-state electrolytes, and Zr is present in the groundThe abundance In the shell is far larger than elements such as In, Sc, Y, Tb-Lu and the like which form other chloride solid electrolytes; accordingly, ZrCl as a starting Material₄The price of (A) is several orders of magnitude lower than that of other raw materials for chloride solid electrolytes, besides that, Li₂ZrCl₆Is stable in an atmosphere of 5% humidity, and therefore, the inorganic chloride solid state electrolyte material provided by the present application has the advantages of low cost and high moisture resistance. Specifically, the embodiment of the invention discloses an inorganic chloride solid electrolyte material as shown in a formula (I),

Li_xZr_yCl_x+4y (Ⅰ)；

wherein x is more than or equal to 1 and less than or equal to 3, and y is more than or equal to 0.5 and less than or equal to 1.

For the above inorganic chloride solid electrolyte material, the ionic conductivity is more than 1.0X 10^-4S/cm。

In the inorganic chloride solid electrolyte material, x is 1-3, and y is 0.5-1; more specifically, x is 1.5 to 2.5, and y is 0.75 to 0.9. More specifically, the inorganic chloride solid electrolyte material is selected from LiZrCl₅、Li_1.5ZrCl_5.5、Li₂ZrCl₆、Li_2.5ZrCl_6.5、Li₃ZrCl₇Or Li₃Zr_0.75Cl₆. In the inorganic chloride solid electrolyte material, the ionic conductivity of the material beyond the x and y ranges is relatively low, and the material is air-sensitive.

The application also provides a preparation method of the inorganic chloride solid electrolyte material, which comprises the following steps:

LiCl and ZrCl are added according to stoichiometric ratio₄And (5) ball milling and mixing.

In the process of preparing the inorganic chloride solid electrolyte material, the LiCl and ZrCl raw materials are taken according to the specific values of x and y and the stoichiometric ratio₄Ball milling and mixing to obtain the inorganic chloride solid electrolyte material according with the proportion. The ball milling is a mixing means well known to those skilled in the art, and the specific embodiment thereof is not particularly limited herein. After ball milling and mixingIn the process, the ball-milling ball-material ratio is (5-20): 1, and in a specific embodiment, the ball-milling ball-material ratio is (10-15): 1; the rotation speed of the ball mill is 200-1000 r/min, and in a specific embodiment, the rotation speed of the ball mill is 400-800 r/min; the ball milling time is 12-48 h, and in a specific embodiment, the ball milling time is 24 h.

To facilitate the study of the inorganic chloride solid state electrolyte material, the mixing further includes drying and pressing; the drying is at 5% humidity N₂The drying time is 12-36 h, and in a specific embodiment, the drying time is 24 h; the pressure of cold pressing is 300-500 MPa, and in a specific embodiment, the pressure of pressing is 350-450 MPa.

The application also provides a lithium ion battery, which comprises a positive electrode, a negative electrode and an electrolyte, wherein the electrolyte is the inorganic chloride solid electrolyte material.

Ultra-low cost inorganic chloride solid electrolyte (Li) developed by the invention_xZr_yCl_x+4yX is more than or equal to 1 and less than or equal to 3, and y is more than or equal to 0.5 and less than or equal to 1), and has higher ionic conductivity and moisture resistance at 5 percent of humidity; further, it uses ZrCl of ultra low cost₄As a raw material, the low requirement of the electrolyte on humidity in the preparation process can further reduce the preparation difficulty, so that the large-scale industrial application of the inorganic chloride becomes possible, and the industrialization process of the solid-state battery is further promoted.

For further understanding of the present invention, the following examples are provided to illustrate the inorganic chlorinated solid electrolyte and the preparation method and application thereof, and the scope of the present invention is not limited by the following examples.

Example 1

This example is Li₂ZrCl₆Preparation of solid electrolyte material and moisture stability study.

For large-scale industrial application, the price of raw materials for preparing the high ionic conductivity inorganic chloride electrolyte material and the content in the earth crust are crucial. Only the raw materials with low cost and large abundance of corresponding elements are more likely to lead the inorganic chloride electrolyte material to be applied to the large-scale industry, and promote the industrialization process of the solid-state battery. Therefore, Zr with the price far lower than that of In, Sc, Y and Tb-Lu is selected as an element for developing a novel inorganic chloride solid electrolyte.

Respectively weighing LiCl and ZrCl in a glove box according to stoichiometric ratio₄Pouring the mixture into a 80mL ball milling tank for ball milling and mixing, wherein the ball material ratio is 10: 1; taking out the sealed glove box, and carrying out ball milling by adopting a high-energy ball mill, wherein the ball milling speed is 500 revolutions per minute, and the ball milling time is 24 hours; obtaining Li after ball milling₂ZrCl₆A solid electrolyte material.

Li obtained by high-energy ball milling₂ZrCl₆Placing the solid electrolyte material in a humidity N of 5%₂The powder before and after moisture exposure is directly cold-pressed into small pieces with the diameter of 10mm and the thickness of 1.5mm by a mould under the pressure of 380MPa, then gold is sprayed on the surface by a gold spraying instrument, and then the ionic conductivity of the material is measured at room temperature; li₂ZrCl₆The X-ray diffraction patterns and the ionic conductivity curves of the solid electrolyte material before and after the solid electrolyte material is exposed to moisture are shown in figures 1 and 2, and the results show that the solid electrolyte material hardly reacts with water in 5% of moisture; under the condition of room temperature, Li after ball milling₂ZrCl₆The lithium ion conductivity of the solid electrolyte material was 4.8X 10^-4S/cm, which indicates that the lithium ion solid electrolyte provided by the embodiment is a super ion conductor at room temperature.

Example 2

This example is LiZrCl₅Preparation of solid electrolyte material and moisture stability study.

Respectively weighing LiCl and ZrCl in a glove box according to stoichiometric ratio₄Respectively pouring the mixture into a 80mL ball milling tank for ball milling and mixing, wherein the ball material ratio is 10: 1; and taking out the sealed glove box, and performing ball milling by adopting a high-energy ball mill at a ball milling rotating speed of 500 revolutions per minute for 24 hours. And after the ball milling is finished, taking the materials out of the glove box for later use.

Ball milling high energyThe resulting LiZrCl₅Placing the solid electrolyte material in a humidity N of 5%₂The powder before and after moisture exposure is directly cold-pressed into small pieces with the diameter of 10mm and the thickness of 1.5mm by a mould under the pressure of 380MPa, then gold is sprayed on the surface by a gold spraying instrument, and then the ionic conductivity of the material is measured at room temperature. LiZrCl₅The X-ray diffraction patterns and the ion conductivity curves of the solid electrolyte material before and after the solid electrolyte material is exposed in moisture are shown in figures 3 and 4, and the results show that LiZrCl is subjected to ball milling under the room temperature condition₅The lithium ion conductivity of the solid electrolyte material was 1.5X 10^-4S/cm, which indicates that the lithium ion solid electrolyte provided by the embodiment is a super ion conductor at room temperature.

Example 3

This example is Li_1.5ZrCl_5.5Preparation of solid electrolyte material and moisture stability study.

Respectively weighing LiCl and ZrCl in a glove box according to stoichiometric ratio₄Respectively pouring the mixture into a 80mL ball milling tank for ball milling and mixing, wherein the ball material ratio is 10: 1; and taking out the sealed glove box, and performing ball milling by adopting a high-energy ball mill at a ball milling rotating speed of 500 revolutions per minute for 24 hours. And after the ball milling is finished, taking the materials out of the glove box for later use.

Li obtained by high-energy ball milling_1.5ZrCl_5.5Placing the solid electrolyte material in a humidity N of 5%₂The powder before and after moisture exposure is directly cold-pressed into small pieces with the diameter of 10mm and the thickness of 1.5mm by a mould under the pressure of 380MPa, then gold is sprayed on the surface by a gold spraying instrument, and then the ionic conductivity of the material is measured at room temperature. Li_1.5ZrCl_5.5The X-ray diffraction patterns and ionic conductivity curves of the solid electrolyte material before and after exposure to moisture are shown in fig. 5 and 6; the results show that Li is present after ball milling at room temperature_1.5ZrCl_5.5The lithium ion conductivity of the solid electrolyte material was 1.6X 10^-4S/cm, which indicates that the lithium ion solid electrolyte provided by the embodiment is a super ion conductor at room temperature.

Example 4

This example is Li_2.5ZrCl_6.5Preparation of solid electrolyte material and moisture stability study.

Respectively weighing LiCl and ZrCl in a glove box according to stoichiometric ratio₄Respectively pouring the mixture into a 80mL ball milling tank for ball milling and mixing, wherein the ball material ratio is 10: 1; taking out the sealed glove box, and carrying out ball milling by adopting a high-energy ball mill, wherein the ball milling speed is 500 revolutions per minute, and the ball milling time is 24 hours; and after the ball milling is finished, taking the materials out of the glove box for later use.

Li obtained by high-energy ball milling_2.5ZrCl_6.5Placing the solid electrolyte material in a humidity N of 5%₂The powder before and after moisture exposure is directly cold-pressed into small pieces with the diameter of 10mm and the thickness of 1.5mm by a mould under the pressure of 380MPa, then gold is sprayed on the surface by a gold spraying instrument, and then the ionic conductivity of the material is measured at room temperature. Li_2.5ZrCl_6.5The X-ray diffraction patterns and ionic conductivity curves of the solid electrolyte material before and after exposure to moisture are shown in fig. 7 and 8; the results show that Li is present after ball milling at room temperature_2.5ZrCl_6.5The lithium ion conductivity of the solid electrolyte material was 3.1X 10^-4S/cm, which indicates that the lithium ion solid electrolyte provided by the embodiment is a super ion conductor at room temperature.

Example 5

This example is Li₃ZrCl₇Preparation of solid electrolyte material and moisture stability study.

Respectively weighing LiCl and ZrCl in a glove box according to stoichiometric ratio₄Respectively pouring the mixture into a 80mL ball mill tank for ball milling and mixing, wherein the ball-material ratio is 10: 1. And taking out the sealed glove box, and performing ball milling by adopting a high-energy ball mill at a ball milling rotating speed of 500 revolutions per minute for 24 hours. And after the ball milling is finished, taking the materials out of the glove box for later use.

Li obtained by high-energy ball milling₃ZrCl₇Placing the solid electrolyte material in a humidity N of 5%₂After 24 hours, the powder before and after moisture exposure was cold-pressed to a diameter of 10m using a die directly under a pressure of 380MPam, the thickness of the small piece is about 1.5mm, gold is sprayed on the surface of the small piece by a gold spraying instrument, and then the ionic conductivity of the material is measured at room temperature. Li₃ZrCl₇The X-ray diffraction patterns and ion conductivity curves of the solid electrolyte material before and after exposure to moisture are shown in fig. 9 and 10, and the results show that Li is ball-milled under room temperature conditions₃ZrCl₇The lithium ion conductivity of the solid electrolyte material was 2.7X 10^-4S/cm. The lithium ion solid electrolyte provided by the embodiment is a super ion conductor at room temperature.

Example 6

This example is Li₃Zr_0.75Cl₆Preparation of solid electrolyte material and moisture stability study.

Respectively weighing LiCl and ZrCl in a glove box according to stoichiometric ratio₄Respectively pouring the mixture into a 80mL ball milling tank for ball milling and mixing, wherein the ball material ratio is 10: 1; taking out the sealed glove box, and carrying out ball milling by adopting a high-energy ball mill, wherein the ball milling speed is 500 revolutions per minute, and the ball milling time is 24 hours; and after the ball milling is finished, taking the materials out of the glove box for later use.

Li obtained by high-energy ball milling₃Zr_0.75Cl₆Placing the solid electrolyte material in a humidity N of 5%₂The powder before and after moisture exposure is directly cold-pressed into small pieces with the diameter of 10mm and the thickness of 1.5mm by a mould under the pressure of 380MPa, then gold is sprayed on the surface by a gold spraying instrument, and then the ionic conductivity of the material is measured at room temperature. Li₃Zr_0.75Cl₆The X-ray diffraction patterns and ion conductivity curves of the solid electrolyte material before and after exposure to moisture are shown in FIGS. 11 and 12, and the results show that Li is obtained after ball milling under room temperature₃Zr_0.75Cl₆The lithium ion conductivity of the solid electrolyte material was 2.4X 10^-4S/cm, which indicates that the lithium ion solid electrolyte provided by the embodiment is a super ion conductor at room temperature.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.