Halide solid state electrolyte, electrode, cell, battery, and power device

Abstract

This invention discloses a halide solid electrolyte, electrodes, a cell, a single cell, and an electrical device. The structural formula of the halide solid electrolyte is Li. 3a MO 3a X 5‑3a This halide solid electrolyte possesses extremely high ionic conductivity. Its synthesis is a solid-phase synthesis that does not require high temperatures, making the particle size and ratio of raw materials extremely important. By refining the raw materials, the synthesis time can be further shortened in high-energy ball milling equipment, increasing production capacity and reducing energy consumption. In addition, another fatal weakness of this halide is its instability with lithium metal. It can undergo side reactions with the lithium anode, leading to interface deterioration. Therefore, it is more likely to be used for coating cathode materials and as a solid electrolyte on the cathode side in the future.

Description

Technical Field

[0001] This invention relates to the technical field of a halide solid electrolyte, electrode, cell, single cell and electrical device for lithium-ion batteries, and particularly to a halide solid electrolyte, cell, single cell and electrical device, as well as its preparation method and application. Background Technology

[0002] Liquid lithium batteries have reached their energy density limits and pose a risk of thermal runaway. To meet the demands for higher safety and energy density, solid-state batteries have emerged. As a representative of next-generation battery technology, solid-state batteries are gradually becoming a research hotspot in the new energy field due to their advantages such as high safety, high energy density, and long lifespan.

[0003] Halogen solid electrolytes (such as Li3YCl6 and LiMOCl4) are considered a promising candidate for all-solid-state batteries, with their biggest advantage being their versatility. They inherently possess high voltage stability (>4V), allowing them to directly integrate with high-energy-density ternary cathodes (such as NCM811) without requiring an additional protective layer like sulfides, thus simplifying battery manufacturing. Simultaneously, they exhibit similar good mechanical ductility to sulfides, allowing for tight bonding with electrode materials through cold pressing, reducing interfacial impedance. Furthermore, they are relatively insensitive to moisture in the air, unlike sulfides which react with water to produce highly toxic hydrogen sulfide, resulting in lower production environment requirements and greater suitability for mass production.

[0004] Traditional halide solid electrolytes mainly refer to ternary systems based on trivalent metal chlorides, with typical examples including Li3YCl6, Li3InCl6, and Li3ScCl6. The room-temperature ionic conductivity of these materials is generally in the moderate range of 0.5 to 3 mS / cm (on the order of 10⁻³ S / cm). Overall, while the conductivity of traditional halides is better than that of most oxides, it is usually lower than that of sulfide electrolytes.

[0005] Traditional halide synthesis employs solid-state methods, which rely heavily on the uniform distribution of materials according to stoichiometric ratios and high-energy ball milling. However, most synthesis methods neglect material refinement and uniform mixing. Our company has discovered through experiments that refining the particle size of raw materials to a certain extent can effectively reduce ball milling time, energy consumption, and increase mass production capacity. Li, synthesized through a unique process... 3x MO 3x Cl 5-3x Halogen electrolytes have extremely high ionic conductivity (≥10 mS / cm); however, another fatal weakness of halogens is their instability with lithium metal. They can react with lithium anodes, leading to interface deterioration. Therefore, they are more likely to be used for coating cathode materials and as solid electrolytes on the cathode side in the future. Summary of the Invention

[0006] The purpose of this invention is to provide a halide solid electrolyte, its battery cell, and electrical equipment. Experiments have shown that refining the particle size of raw materials to a certain extent can effectively reduce ball milling time, reduce energy consumption, and improve mass production capacity; Li synthesized through a unique process... 3x MO 3x Cl 5-3x Halogen electrolytes possess extremely high ionic conductivity.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a halide solid electrolyte, a battery cell, a battery cell thereof, and an electrical device thereof, wherein the material is LMO. b Precursors and lithium halides and MCl c It is prepared by high-energy ball milling.

[0009] As a specific technical solution, the chemical structural formula of this halide solid electrolyte is Li 3a MO 3a M 5-3a Where 0 < a ≤ 1, 0 < b ≤ 4, 0 < c ≤ 6, and the above are all mol ratios, where a can be any numerical ratio of 0 or 1; where b can be any numerical ratio of 1, 2, 3, or 4; and where c can be any numerical ratio of 1, 2, 3, 4, 5, or 6.

[0010] Secondly, the present invention provides a method for preparing the above-mentioned composite material, comprising the following steps:

[0011] This invention also discloses a method for preparing a halide solid electrolyte, a cell, a single battery, and an electrical device, characterized by comprising the following steps:

[0012] Its characteristic includes the following steps:

[0013] S1, LMO b Preparation of precursor: Weigh lithium source and oxide of M according to the molar ratio; mix uniformly; refine the D50 particle size of the mixture to a certain range; further dry to control the water content ≤500ppm;

[0014] S2. Sinter the above raw materials at high temperature under a certain atmosphere for a period of time; then grind them again to refine the particle size within a certain range and dry them for later use; control the water content.

[0015] S3. Under an inert atmosphere, the remaining raw materials, lithium halides and M halides, are ground to a certain particle size and then dried for later use; the water content is controlled.

[0016] S4. After mixing the raw materials from S2 and S3 in a certain stoichiometric ratio, load them into a high-energy ball mill and ball mill them for a certain period of time under an inert atmosphere.

[0017] As a specific technical solution, in step S1 of the preparation method of this halide solid electrolyte, the D50 particle size is controlled within a certain range of 0≤D50≤5μm; further, it can be 0≤D50≤1μm; even further, it can be 100nm≤D50≤500nm. We found that the smaller the particle size, the shorter the sintering time and the better the sintered LMO. b The higher the phase purity of the precursor.

[0018] As a specific technical solution, the LMO in step S2 of the preparation method of this halide solid electrolyte... b The D50 particle size after precursor sintering is controlled within a certain range of 0≤D50≤5μm; further, it can be 0≤D50≤1μm; even further, it can be 100nm≤D50≤500nm. We found that the smaller the particle size, the shorter the mixing time and high-energy ball milling time of the subsequent S3 and S4 steps.

[0019] As a specific technical solution, the lower the water content in steps S1 to S3 of the preparation method of the halide solid electrolyte, the better; we found that the lower the water content, the higher the conductivity of the prepared halide ions.

[0020] As a specific technical solution, in step S3 of the preparation method of this halide solid electrolyte, lithium halide and MCl... c Particle size control ≤5μm: further, it can be 0≤D50≤1μm; even further, it can be 100nm≤D50≤500nm; we found that the smaller the particle size, the shorter the mixing time and high-energy ball milling time of the subsequent S3 and S4 steps.

[0021] As a specific technical solution, another fatal weakness of this halide is its instability with lithium metal. It will undergo side reactions with the lithium anode, leading to interface deterioration. Therefore, it is more likely to be used for coating cathode materials and as a solid electrolyte on the cathode side in the future. The cathode material can be a composite cathode material layer containing ternary (high nickel, medium nickel, low nickel, and single crystal, polycrystalline), lithium iron phosphate, lithium cobalt oxide, lithium nickel oxide, lithium manganese iron phosphate, or lithium-rich manganese-based cathode materials. The solid electrolyte on the cathode side can be a composite solid electrolyte prepared by combining this halide with other halide electrolytes, sulfide electrolytes, and polymer electrolytes. The solid cathode electrode is used to form the above-mentioned cathode system. This solid cathode electrode can also be further matched with the anode material.

[0022] The negative electrode material can be a composite negative electrode material layer containing graphite, silicon oxide, silicon carbon, CVD silicon carbon, or no negative electrode structure; the electrolyte can be a composite electrolyte layer containing polymer solid electrolyte, oxide solid electrolyte, halide solid electrolyte, or sulfide solid electrolyte layer.

[0023] Thirdly, the present invention also provides the application of halide solid electrolyte materials prepared by halide solid electrolyte, cell and battery cell and electrical device preparation method in batteries, wherein the batteries include any one of lithium-ion batteries, solid batteries and semi-solid batteries.

[0024] Compared with existing technologies, experiments have shown that refining the particle size of raw materials to a certain extent can effectively reduce ball milling time, reduce energy consumption, and improve mass production capacity; Li synthesized through a unique process 3x MO 3x Cl 5-3x Halogen electrolytes possess extremely high ionic conductivity, ≥10 mS / cm. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Unless otherwise specified, the experimental methods used in the examples and comparative examples are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0027] The present invention will be further described in detail below through detailed embodiments.

[0028] Example 1

[0029] This embodiment provides a method for preparing a halide solid electrolyte, a battery cell, and its battery unit and electrical equipment, wherein the structural formula is LiTaOCl4. The wet preparation method of this halide solid electrolyte is as follows:

[0030] Preparation of S1 and LiTaO3 precursors: Weigh lithium carbonate and tantalum oxide according to the molar ratio; add deionized water and control the solid content ≤35%; after uniform mixing, perform wet sand milling; refine the D50 particle size of the above mixture to ≤5μm; then spray dry; further dry to control the water content ≤300ppm;

[0031] S2. Sinter the above raw materials at high temperature under a certain atmosphere for 10 hours; then grind them again to refine the particle size to D50. After the particle size is controlled to ≤5μm, dry them for later use; control the water content to ≤300ppm.

[0032] S3. Under an inert atmosphere, the remaining raw materials, lithium chloride and tantalum chloride, are ground and refined to a D50 particle size of ≤5μm for later use; the water content is controlled to ≤300ppm.

[0033] S4. Mix the raw materials from S2 and S3 in a certain stoichiometric ratio until homogeneous; load them into a high-energy ball mill; and ball mill for 72 hours under an inert atmosphere.

[0034] Example 2

[0035] This embodiment provides a method for preparing a halide solid electrolyte, a battery cell, and its battery unit and electrical equipment, wherein the structural formula is LiTaOCl4. The wet preparation method of this halide solid electrolyte is as follows:

[0036] Preparation of S1 and LiTaO3 precursors: Weigh lithium carbonate and tantalum oxide according to the molar ratio; add deionized water and control the solid content ≤35%; after uniform mixing, perform wet sand milling; refine the D50 particle size of the above mixture to ≤1μm; then spray dry; further dry to control the water content ≤300ppm;

[0037] S2. Sinter the above raw materials at high temperature under a certain atmosphere for 10 hours; then grind them again to refine the particle size to D50. After the particle size is controlled to ≤1μm, dry them for later use; control the water content to ≤300ppm.

[0038] S3. Under an inert atmosphere, the remaining raw materials, lithium chloride and tantalum chloride, are ground to a D50 particle size of ≤1μm for later use; the water content is controlled to ≤300ppm.

[0039] S4. Mix the raw materials from S2 and S3 at a certain stoichiometric ratio until uniform; load them into a high-energy ball mill; and ball mill for 48 hours under an inert atmosphere.

[0040] Example 3

[0041] This embodiment provides a method for preparing a halide solid electrolyte, a battery cell, and its battery unit and electrical equipment, wherein the structural formula is LiTaOCl4. The wet preparation method of this halide solid electrolyte is as follows:

[0042] Preparation of S1 and LiTaO3 precursors: Weigh lithium source and tantalum oxide according to the molar ratio; add deionized water and control the solid content ≤35%; after uniform mixing, perform wet sand milling; refine the D50 particle size of the above mixture to ≤500nm; then spray dry; further dry to control the water content ≤300ppm;

[0043] S2. Sinter the above raw materials at high temperature under a certain atmosphere for 10 hours; then grind them again to refine the particle size to D50. After the particle size is controlled to ≤500nm, dry them for later use; control the water content to ≤300ppm.

[0044] S3. Under an inert atmosphere, the remaining raw materials, lithium chloride and tantalum chloride, are ground and refined to a D50 particle size of ≤500nm for later use; the water content is controlled to ≤300ppm.

[0045] S4. Mix the raw materials from S2 and S3 evenly according to a certain stoichiometric ratio; load them into a high-energy ball mill; and ball mill for 24 hours under an inert atmosphere.

[0046] Example 4

[0047] This embodiment provides a method for preparing a halide solid electrolyte, a battery cell, and its battery unit and electrical equipment, wherein the structural formula is LiNbOCl4. The wet preparation method of this halide solid electrolyte is as follows:

[0048] Preparation of S1 and LiNbO3 precursor: Weigh lithium source and tantalum oxide according to the molar ratio; add deionized water and control the solid content ≤35%; after uniform mixing, perform wet sand milling; refine the D50 particle size of the above mixture to ≤500nm; then spray dry; further dry to control the water content ≤300ppm;

[0049] S2. Sinter the above raw materials at high temperature under a certain atmosphere for 10 hours; then grind them again to refine the particle size to D50. After the particle size is controlled to ≤500nm, dry them for later use; control the water content to ≤300ppm.

[0050] S3. Under an inert atmosphere, the remaining raw materials, lithium chloride and niobium chloride, are ground to a D50 particle size of ≤500nm for later use; the water content is controlled to ≤300ppm.

[0051] S4. Mix the raw materials from S2 and S3 evenly according to a certain stoichiometric ratio; load them into a high-energy ball mill; and ball mill for 24 hours under an inert atmosphere.

[0052] Comparative Example 1

[0053] This embodiment provides a method for preparing a halide solid electrolyte, a battery cell, and its battery unit and electrical equipment, wherein the structural formula is LiNbOCl4. The wet preparation method of this halide solid electrolyte is as follows:

[0054] Preparation of S1 and LiNbO3 precursors: Weigh lithium source and tantalum oxide according to the molar ratio; add deionized water and control the solid content ≤35%; after uniform mixing, perform wet sand milling; refine the D50 particle size of the above mixture to ≤10μm; then spray dry; further dry to control the water content ≤2000ppm;

[0055] S2. Sinter the above raw materials at high temperature under a certain atmosphere for 10 hours; then grind them again to refine the particle size to D50. After the particle size is controlled to ≤10μm, dry them for later use; control the water content to ≤2000ppm.

[0056] S3. Under an inert atmosphere, the remaining raw materials, lithium chloride and niobium chloride, are ground to a D50 particle size of ≤10μm for later use; the water content is controlled to ≤300ppm.

[0057] S4. Mix the raw materials from S2 and S3 in a certain stoichiometric ratio until homogeneous; load them into a high-energy ball mill; and then ball mill for 100 hours under an inert atmosphere.

[0058] Comparative Example 2

[0059] This embodiment provides a method for preparing a halide solid electrolyte, a battery cell, and its battery unit and electrical equipment, wherein the structural formula is LiTaOCl4. The wet preparation method of this halide solid electrolyte is as follows:

[0060] Preparation of S1 and LiTaO3 precursors: Weigh lithium carbonate and tantalum oxide according to the molar ratio; add deionized water and control the solid content ≤35%; after uniform mixing, perform wet sand milling; refine the D50 particle size of the above mixture to ≤10μm; then spray dry; further dry to control the water content ≤2000ppm;

[0061] S2. Sinter the above raw materials at high temperature under a certain atmosphere for 10 hours; then grind them again to refine the particle size to D50. After the particle size is controlled to ≤10μm, dry them for later use; control the water content to ≤2000ppm.

[0062] S3. Under an inert atmosphere, the remaining raw materials, lithium chloride and tantalum chloride, are ground to a D50 particle size of ≤10μm for later use; the water content is controlled to ≤300ppm.

[0063] S4. After uniformly mixing the raw materials from S2 and S3 according to a certain stoichiometric ratio, load them into a high-energy ball mill and ball mill for 100 hours under an inert atmosphere. Press the powders from Examples 1-4 and Comparative Examples 1-2 into cylinders with a diameter of 1 cm and a thickness of 1 cm in a mold. Add carbon-coated aluminum foil to both sides. Test the ionic conductivity impedance using an electrochemical workstation under a pressure of 20 MPa. The frequency range is 10 μHz–32 MHz, and the resolution is 1 μΩ. The formula for calculating ionic conductivity is: σ = d / Re × S, where d is the thickness of the sample (cm); Re is the bulk impedance of the sample (ohms), which can be obtained from the intersection of the semicircle and the oblique line in the Nyquist plot of the electrochemical impedance spectroscopy; and S is the effective area of ​​the electrode (cm²). 2 ).

[0064] The powders from Examples 1-12 and Comparative Examples 1-2 were further combined with a positive electrode material (Ni88 single crystal: Comparative Example 2 = 7:3), a negative electrode material (graphite negative electrode: Examples 1-12 and Comparative Examples 1-2 = 7:3), and a solid electrolyte (Comparative Example 2) to assemble a battery. The battery was tested within a charge / discharge range of 2.5V-4.2V, with a test current of 0.1C.

[0065] Table 1 Test data of batteries made in different embodiments

[0066] Example <![CDATA[Ionic conductivity (S.cm -1 )]]> 1 12.69 2 12.98 3 13.42 4 10.93 Comparative Example 1 10.28 Comparative Example 2 12.24

[0067] As can be seen from Table 1 above, Examples 1-3 and Comparative Example 2 used the same structural formula, LiTaOCl4, and controlled the water content to ≤300ppm during the process. Simultaneously, the particle size was controlled to ≤5μm, ≤1μm, and ≤500nm for Examples 1-3, respectively; while for Comparative Example 2, the particle size was controlled to ≤10μm; its ionic conductivity was 12.24 S·cm. -1 Increased to 12.69, 12.98, and 13.42 S. cm -1 Furthermore, Example 4 and Comparative Example 2 synthesized the same structural formula, LiNbOCl4, and similarly controlled the water content to ≤300ppm during the process. The particle size was also controlled to ≤500nm in Example 4 and ≤10μm in the Comparative Example; its ionic conductivity ranged from 10.28 S·cm. -1 Increased to 10.93 S. cm -1 The experimental results show that controlling the particle size during the process can effectively improve the ionic conductivity of solid electrolytes; at the same time, it can reduce energy consumption, increase production capacity, and reduce costs.

[0068] The halide solid electrolyte, cell, single cell and electrical device provided by the present invention can be applied to lithium-ion batteries, solid batteries, semi-solid batteries, negative electrode-free batteries and other batteries.

[0069] The above embodiments are merely illustrative of the concept and technical solution of the present invention and are not intended to limit the present invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A halide solid-state electrolyte, an electrode, a battery cell, a single battery and an electrical device, the halide solid-state electrolyte has a main structure formula of Li 3a MO 3a X 5-3a .

2. As claimed in claim 1, the feature is that Li 3a MO 3a X 5-3a where M can be one or more of: V, Nb, Ta, Sb, Bi, As, Hf, etc.

3. According to claim 1, the feature is that, In the chemical structural formulas mentioned above, the range of 'a' is 0 < a ≤ 1; all of the above are mol ratios.

4. According to claim 1, the feature is that, The halide electrolyte has a structural formula Li 3a MO 3a X 5-3a X in the formula can be one or a combination of I, Cl, Br, F, etc.

5. This invention also discloses a method for preparing a halide solid electrolyte, a cell, a single battery, and an electrical device, characterized in that... Includes the following steps: S1, LMO b Precursor preparation: Weigh the lithium source and the oxide of M according to the molar ratio; mix them uniformly; refine the D50 particle size of the mixture to a certain range; further dry to control the water content; S2. Sinter the above raw materials at high temperature under a certain atmosphere for a period of time; Then, the particles are further refined by grinding to control the particle size within a certain range before drying for later use. S3. Under the protection of an inert atmosphere, the remaining raw materials, lithium halide and M halide, are ground and refined to a certain particle size for later use. S4. After mixing the raw materials from S2 and S3 in a certain stoichiometric ratio, load them into a high-energy ball mill and ball mill them for a certain period of time under an inert atmosphere.

6. According to claim 5, the lithium source in step S1 of the preparation method is one or more of lithium hydroxide, lithium carbonate, lithium oxide, lithium oxalate, etc.; the M source is mainly one or more of oxides, hydroxides, carbonates, etc. of M; the grinding and refining can be dry grinding (sand milling), wet grinding (sand milling), mechanical milling, ball milling, etc. If wet grinding is used, further drying is required, and the drying equipment can be one or more of spray drying, centrifugal drying, oven drying, etc.; if the above is wet grinding, the solvent can be deionized water, ethanol, methanol, acetone, etc.

7. According to claim 5, the sintering atmosphere in step S2 of the preparation method can be one or a combination of air, dry air, nitrogen, oxygen, argon, etc.; the sintering temperature is 700 ≤ 1200℃; the sintering time is based on the LMO formed. b The phase of the precursor is determined; where b≤4; the higher the sintering temperature, the shorter the sintering time; the refining treatment method can be dry grinding (sand milling), wet grinding (sand milling), mechanical milling, ball milling, etc.; the particle size control is 0≤D50≤5μm, and the smaller the particle size, the better.

8. The method for preparing S3 according to claim 5, characterized in that, In step S3, the lithium halide is LiCl, LiBr, LiF, or LiI; the M halide is MClc; where C ≤ 6; the grinding and refining process is achieved by using the above grinding method to control the particle size of the raw material within the specified particle size control range of 0 ≤ D50 ≤ 5 μm, with smaller particle size being better.

9. The method for preparing S4 according to claim 5, characterized in that, In step S4, the certain stoichiometric ratio refers to the final chemical structural formula; the inert atmosphere is as described above; and the ball milling time is ≤72h.

10. The halide solid electrolyte material according to claim 1 or the halide solid electrolyte material prepared by any one of claims 1 to 9 can be matched with a solid positive electrode, a solid negative electrode and an electrolyte layer to assemble into a solid battery system, and can be used in electrode sheets, batteries, battery packs and electrical devices, wherein the battery includes any one of lithium-ion batteries, solid batteries and semi-solid batteries.