Halide nanomaterials, methods of making, and applications in solid-state batteries

Abstract

The application discloses a halide nanomaterial and a preparation method and application thereof in a solid-state battery, and comprises the following steps: after halide raw materials are synthesized through wet ball milling and dried, the halide nanomaterial with controllable size is obtained through three-stage gradient temperature control in an inert atmosphere, recooling, crushing and screening, wherein the three-stage gradient temperature control is as follows: the first temperature rising stage is a low-temperature desorption stage, rising from room temperature to 120-170 DEG C; the second temperature rising stage is a medium-temperature crystallization stage, rising from 120-170 DEG C to 200-220 DEG C; and the third temperature rising stage is a high-temperature densification stage, rising from 200-220 DEG C to 250-300 DEG C. The application makes the particle size change controllable in general, finally realizes the beneficial effect that the particle size D50 is less than or equal to 0.9 microns and the deviation is less than or equal to 5%, overcomes the problem of high particle size dispersion of the existing synthesis method, and improves the morphology and dispersibility of the nanomaterial: regular circular morphology + no agglomeration characteristics, improves the particle packing density, reduces the interface contact resistance, and solves the problem of poor interface compatibility of macroscopic particles.

Description

Technical Field

[0001] This invention relates to the field of solid-state batteries, specifically to a halide nanomaterial, its preparation method, and its application in solid-state batteries. Background Technology

[0002] Solid-state batteries, as next-generation high-performance energy storage devices, rely on the interfacial compatibility, ion transport efficiency, and structural stability of electrolyte and electrode materials for their core performance characteristics (such as energy density, cycle stability, and safety). Halogen materials, due to their high ionic conductivity (meeting the rapid ion transport requirements of solid-state batteries) and wide electrochemical window (suitable for high-voltage cathode materials), have become a research hotspot for solid-state battery electrolytes and electrode modification materials. However, existing halide materials are mostly macroscopic particles, presenting three major challenges:

[0003] (1) The small specific surface area results in a limited interfacial contact area with the electrode material and a high interfacial contact resistance;

[0004] (2) The long ion diffusion path reduces ion transport efficiency;

[0005] (3) Irregular morphology and easy agglomeration affect the batch stability of materials and make it difficult to meet the consistency requirements of solid-state batteries.

[0006] Nanoscale halide materials can address the aforementioned issues by increasing specific surface area (enhancing interfacial contact) and shortening ion transport distance (improving transport efficiency). However, existing synthesis methods (such as solid-state methods, melt methods, and aqueous methods) suffer from drawbacks such as difficulty in precisely controlling particle size (deviations often exceeding 10%) and easy agglomeration or irregular morphology. This leads to poor batch-to-batch stability of the materials, failing to meet the consistency requirements of solid-state batteries and limiting their practical application. Therefore, developing a halide nanomaterial synthesis technology that can precisely control particle size and morphology is of great significance for overcoming the performance bottleneck of solid-state batteries. Summary of the Invention

[0007] To address the aforementioned problems, the present invention aims to provide a halide nanomaterial, its preparation method, and its application in solid-state batteries. This halide nanomaterial utilizes a segmented sintering process to control particle size variation at each stage, resulting in largely controllable particle size changes. Ultimately, it achieves a particle size D50 ≤ 0.9 μm with a deviation ≤ 5%, overcoming the high particle size dispersion problem of existing synthesis methods. This improves the morphology and dispersibility of the nanomaterial: a regular circular morphology with no agglomeration, increasing particle packing density (≥ 75%), reducing interfacial contact resistance, and solving the problem of poor macroscopic particle interfacial compatibility.

[0008] This invention is achieved through the following technical solution:

[0009] A method for preparing halide nanomaterials includes the following steps: halide raw materials are synthesized by wet ball milling and then dried; the materials are then subjected to a three-stage gradient heating control in an inert atmosphere, followed by cooling, crushing, and sieving to obtain halide nanomaterials with controllable size. Specifically, the three-stage gradient heating control is as follows: the first heating stage is a low-temperature desorption stage, increasing from room temperature to 120-170 ℃ and holding for 1-3 h; the second heating stage is a medium-temperature crystallization stage, increasing from 120-170 ℃ to 200-220 ℃ and holding for 2-4 h; the third heating stage is a high-temperature densification stage, increasing from 200-220 ℃ to 250-300 ℃ and holding for 1-2 h.

[0010] The heating rate in the first heating stage is less than the heating rate in the second heating stage, and the heating rate in the third heating stage is less than the heating rate in the second heating stage.

[0011] The heating rate in the first heating stage is 3-8 ℃ / min. The heating rate in the second heating stage is 5-30 ℃ / min. The heating rate in the third heating stage is 3-8 ℃ / min. The cooling process is carried out at a rate of 1 ℃ / min to 3 ℃ / min.

[0012] The wet ball milling synthesis is specifically as follows: an appropriate amount of solvent, dispersant, and weighed raw materials are added to a ball mill jar, and the ball milling reaction is carried out in a ball mill. The solvent is selected from at least one of alkane solvents, benzene solvents, ether solvents, and ketone solvents, and from at least one of dichloromethane, n-heptane, n-decane, p-xylene, trimethylbenzene, anisole, monochlorobenzene, and cyclohexanone. The grinding media during ball milling is zirconia balls with a diameter range of 0.1-10 mm.

[0013] The halide nanomaterial prepared by the method described above has a particle size D50 ≤ 0.9 μm, a particle size deviation ≤ 5%, and a regular circular structure. The single crystal particles have smooth surfaces and clear edges, with an average aspect ratio of 1:1.2-1:1.5 and no obvious agglomeration. The particles are uniformly distributed inside and have a mesoporous structure with a pore size of 5-10 nm, which can serve as additional ion transport channels. The interparticle packing density is ≥ 75%, which is significantly higher than that of traditional angular particles (≤ 60%), which is beneficial for reducing interfacial contact resistance.

[0014] An electrode comprising the halide nanomaterials as described above.

[0015] A battery comprising the electrodes as described above.

[0016] This invention employs gradient temperature-controlled segmented sintering: Addressing the defect of "uncontrollable mesopores," a three-stage gradient temperature control is designed, shortening the high-temperature holding time to 1-2 hours. The first stage: low-temperature desorption stage, with a heating rate of 3-8 ℃ / min, from room temperature to 120-170 ℃, held for 1-3 hours, slowly removing residual solvent and adsorbed water, avoiding rapid heating that could cause solvent boiling and create "ineffective pores," thus ensuring the integrity of the initial particle structure. The second stage: medium-temperature crystallization stage, with a heating rate of 5-30 ℃ / min, from 120-170 ℃ to 200-220 ℃, held for 2-4 hours, rapidly entering the nucleation zone, promoting uniform nucleus growth, inhibiting abnormal grain growth, and laying the foundation for mesopore template shaping. The third stage: high-temperature densification stage, with a heating rate of 3-8 ℃ / min, from 200-220 ℃ to 250-300 ℃, held for 1-2 hours. h. Slow densification: While retaining 5-8 nm mesopores, the packing density is increased to ≥80%; during the cooling stage, the temperature is reduced from 250-300 ℃ to room temperature at a rate of 1-3 ℃ / min, with an inert gas concentration of 99.9%, to avoid stress cracking inside the crystal caused by rapid cooling and to improve the mechanical stability of the particles (compressive strength increased by 15%).

[0017] The first stage has an inert gas volume concentration of 90-92%, the second stage has an inert gas volume concentration of 98-98.5%, and the third stage has an inert gas volume concentration of 99.8-99.9%. Controlling the inert gas concentration at different stages is to improve the ion conductivity of the product.

[0018] The drying method is one of spray drying, vacuum drying, hot air drying, infrared drying, or microwave drying.

[0019] During the sintering stage, the sintering temperature of each subsequent sintering stage is higher than that of the previous sintering stage. In this invention, crushing is generally performed mechanically, including at least one of ball milling, air jet milling, or jaw crushing. Screening employs multi-stage screening, specifically using a vibrating screen or air jet separator, with a screen mesh size ranging from 100 to 5000 mesh; the particle size distribution after screening satisfies D50 ≤ 0.9 μm.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0021] (1) Solve the problem of particle size control: By using the sintering combination process of segmented sintering, the change of particles in each stage is controlled, so that the particle size change is generally controllable, and finally the beneficial effect of particle size D50≤0.9 μm and deviation≤5% is achieved, overcoming the problem of high particle size dispersion in the existing synthesis method.

[0022] (2) Improved morphology and dispersibility: Regular circular morphology + no agglomeration characteristics, increase particle packing density (≥75%), reduce interfacial contact resistance, and solve the problem of poor macroscopic particle interface compatibility;

[0023] (3) Improved synthesis efficiency: Wet synthesis reduces the activation energy of the reaction through mechanical energy, the reaction temperature (50-600 ℃) is lower than that of the traditional solid-phase method (usually >600 ℃), and the reaction time (1-12 h) is shorter than that of the traditional ball milling method (6-12 h), thus saving energy and improving production efficiency;

[0024] (4) Easy to scale up production: The process does not require complex equipment. Wet synthesis, segmented sintering and multi-stage screening steps can all be scaled up industrially, making it suitable for mass production. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 The X-ray diffraction patterns of the Li3InCl6 solid electrolytes prepared in Example 1 and Comparative Example 1 of this invention are shown below.

[0027] Figure 2 This is a SEM image of the Li3InCl6 solid electrolyte prepared in Example 1 of the present invention;

[0028] Figure 3 SEM image of the Li3InCl6 solid electrolyte prepared in Comparative Example 1 of this invention.

[0029] Figure 4 The particle size distribution of the Li3InCl6 solid electrolyte prepared in Example 1 of this invention;

[0030] Figure 5 The ion conductance test curve of the Li3InCl6 solid electrolyte prepared in Example 1 of this invention;

[0031] Figure 6 The ion conductance test curve of the Li3InCl6 solid electrolyte prepared in Comparative Example 1 of this invention is shown. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0033] Example 1:

[0034] (1) Weigh 100 g of LiCl and InCl3·4H2O in a molar ratio of 3:1 according to the stoichiometric ratio of Li3InCl6.

[0035] (2) Add the weighed raw materials and 200 mL of xylene into a ball mill jar and ball mill for 4 h.

[0036] (3) The ball-milled slurry was subjected to vacuum drying at 200 ℃ for 3 h.

[0037] (4) The dried product is sintered in stages. The first sintering stage is: heating from room temperature to 150℃ at a heating rate of 5℃ / min and holding for 2 hours; the second sintering stage is: heating from 150℃ to 210℃ at a heating rate of 10℃ / min and holding for 3 hours; the third sintering stage is: heating from 210℃ to 280℃ at a heating rate of 5℃ / min and holding for 4 hours.

[0038] (5) After the heat treatment, the sample was cooled from 280 °C to room temperature at a rate of 3 °C / min, and then mechanically crushed by a pulverizer to obtain coarse particles of Li3InCl6 solid electrolyte.

[0039] (6) The coarse particles are subjected to ultrasonic vibration multi-stage sieving, and the final product is obtained after sieving. Figure 1 The X-ray diffraction patterns of the Li3InCl6 solid electrolytes prepared in Example 1 and Comparative Example 1 of this invention are shown below. Figure 2 This is a SEM image of the Li3InCl6 solid electrolyte prepared in Example 1 of the present invention. Figure 4 The particle size distribution of the Li3InCl6 solid electrolyte prepared in Example 1 of this invention; Figure 5 The ion conductance test curve of the Li3InCl6 solid electrolyte prepared in Example 1 of this invention;

[0040] Example 2:

[0041] (1) Weigh 100 g of LiCl and YCl3 in a molar ratio of 2:1 according to the stoichiometric ratio of Li3YCl6.

[0042] (2) Add the weighed raw materials and 200 mL of xylene into a ball mill jar and ball mill for 2 h.

[0043] (3) The ball-milled slurry was subjected to vacuum drying at 200 ℃ for 3 h.

[0044] (4) The dried product is sintered in stages. The first sintering stage is: heating from room temperature to 150 ℃ at a heating rate of 5 ℃ / min and holding for 2 h; the second sintering stage is: heating from 150 ℃ to 210 ℃ at a heating rate of 10 ℃ / min and holding for 3 h; the third sintering stage is: heating from 210 ℃ to 300 ℃ at a heating rate of 5 ℃ / min and holding for 4 h.

[0045] (5) After the heat treatment, the sample was cooled from 280 °C to room temperature at a rate of 2 °C / min, and then mechanically crushed by a pulverizer to obtain coarse particles of Li3YCl6 solid electrolyte.

[0046] (6) The coarse particles are subjected to ultrasonic vibration multi-stage sieving, and the final product is obtained after sieving.

[0047] Example 3:

[0048] (1) Weigh 100 g of LiCl and ZrCl4 in a molar ratio of 2:1 according to the stoichiometric ratio of Li2ZrCl6.

[0049] (2) Add the weighed raw materials and 200 mL of xylene into a ball mill jar and ball mill for 2 h.

[0050] (3) The ball-milled slurry was subjected to vacuum drying at 200 ℃ for 3 h.

[0051] (4) The dried product is sintered in stages. The first sintering stage is: heating from room temperature to 150℃ at a heating rate of 5℃ / min and holding for 2 hours; the second sintering stage is: heating from 150℃ to 210℃ at a heating rate of 10℃ / min and holding for 3 hours; the third sintering stage is: heating from 210℃ to 280℃ at a heating rate of 5℃ / min and holding for 4 hours.

[0052] (5) After the heat treatment, the sample was cooled from 280 °C to room temperature at a rate of 1 °C / min, and then mechanically crushed by a pulverizer to obtain coarse particles of Li2ZrCl6 solid electrolyte.

[0053] (6) The coarse particles are subjected to ultrasonic vibration multi-stage sieving, and the final product is obtained after sieving.

[0054] Comparative Example 1:

[0055] The specific steps for synthesizing Li3InCl6 solid electrolyte using the traditional aqueous phase method are as follows:

[0056] (1) Weigh 100 g of LiCl and InCl3·4H2O in a molar ratio of 3:1 according to the stoichiometric ratio of Li3InCl6.

[0057] (2) Place the weighed raw materials into a beaker, add 50 ml of deionized water, and stir for 10 minutes.

[0058] (3) Heat the mixed solution to 200 °C in a vacuum drying oven and keep it at that temperature for 3 h.

[0059] (4) After the heat treatment, the sample was naturally cooled to room temperature to obtain Li3InCl6 solid electrolyte. Figure 3 SEM image of the Li3InCl6 solid electrolyte prepared in Comparative Example 1 of this invention. Figure 6 The ion conductance test curve of the Li3InCl6 solid electrolyte prepared in Comparative Example 1 of this invention is shown.

[0060] Comparative Example 2:

[0061] The specific steps for synthesizing Li3YCl6 solid electrolyte using the traditional melt method are as follows:

[0062] (1) Weigh 100 g of LiCl and YCl3 in a molar ratio of 2:1 according to the stoichiometric ratio of Li3YCl6.

[0063] (2) Vacuum seal the weighed raw materials.

[0064] (3) Heat the sealed container with the tube to 300 ℃ at a heating rate of 5 ℃ / min and keep it at that temperature for 3 h.

[0065] (4) After the heat treatment, the sample was naturally cooled to room temperature to obtain Li3YCl6 solid electrolyte.

[0066] Comparative Example 3:

[0067] The specific steps for synthesizing Li₂ZrCl₆ solid electrolyte using a traditional solid-state reaction method are as follows:

[0068] (1) Weigh 100 g of LiCl and ZrCl4 in a molar ratio of 2:1 according to the stoichiometric ratio of Li2ZrCl6.

[0069] (2) Add the weighed raw materials into a ball mill jar, and mill at a speed of 200~600 rpm for 6~12 h to obtain Li2ZrCl6 solid electrolyte.

[0070] Comparative Example 4:

[0071] Similar to Example 1, the difference is that the sintering has only one stage: (4) The dried product is sintered in segments. The first sintering stage is: the temperature is raised from room temperature to 280°C at a heating rate of 5°C / min and held for 9 hours.

[0072] Comparative Example 5:

[0073] Similar to Example 1, the difference is that the sintering has only two stages: the first sintering stage is: heating from room temperature to 150°C at a heating rate of 5°C / min and holding at that temperature for 2 hours; the second sintering stage is: heating from 150°C to 280°C at a heating rate of 10°C / min and holding at that temperature for 7 hours.

[0074] Performance testing:

[0075] (1) X-ray diffraction analysis: The phase composition of the Li3InCl6 solid electrolytes prepared in Example 1 and Comparative Example 1 was analyzed using an X-ray diffractometer. The results are as follows: Figure 1 As shown in the figure, the diffraction peaks of the Li3InCl6 solid electrolyte prepared in Example 1 are consistent with those of the standard card PDF#97-008-9617, and the high intensity and narrow half-peak width indicate high purity and good crystallinity of the product. This is essentially consistent with the coarse and fine powders of the Li3InCl6 solid electrolyte prepared in Comparative Example 1.

[0076] (2) SEM analysis: SEM images show that the Li3InCl6 particles prepared by wet method are spherical with uniform particle size distribution and an average particle size of about 0.5 μm.

[0077] (3) Particle size distribution analysis: The particle size distribution results show that the wet-prepared Li3InCl6 has D50=0.89 um and D90=1.82 um.

[0078] (4) Ionic conductivity test: The ionic conductivity of the Li3InCl6 solid electrolytes prepared in Example 1 and Comparative Example 1 was tested using the AC impedance method. The test results showed that the ionic conductivity of the Li3InCl6 solid electrolyte prepared in Example 1 was 1.40 × 10⁻⁶. -3 The S / cm value was higher than that of the solid electrolyte prepared in Comparative Example 1, while the ionic conductivity of the Li3InCl6 solid electrolyte was 1.36 × 10⁻⁶. -3 S / cm.

[0079] The effectiveness of electrolytes can be evaluated based on the following indicators:

[0080] a. Ionic conductance: Measured using AC impedance spectroscopy with an electrochemical workstation;

[0081] b. Particle size distribution: Measured using a dry laser particle size analyzer.

[0082] The test results are shown in Table 1.

[0083] Table 1 Test Results of Examples 1-3 and Comparative Examples 1-3

[0084]

[0085] Conclusion: As can be seen from the examples and comparative examples 4-5, the ion conductivity and particle size distribution of the examples are significantly better than those of comparative examples 4-5. Through the three-stage temperature control of this invention, the particle size change process of nanomaterials can be effectively controlled. In the first stage, the halide material undergoes a slow removal of residual solvent and adsorbed water, avoiding rapid heating that could lead to solvent boiling and the generation of "ineffective pores," thus ensuring the integrity of the initial particle structure. In the second stage, the material rapidly enters the nucleation zone, promoting uniform growth of nuclei and inhibiting abnormal grain growth, laying the foundation for mesoporous template shaping. Slow densification: While retaining 5-8 nm mesopores, the packing density is increased to ≥80%.

[0086] This invention solves the problems of poor interfacial contact, low ion transport efficiency, and poor batch stability of existing halide materials by precisely controlling the particle size and morphology of halide nanomaterials and combining them with an efficient synthesis process. It provides a feasible solution for the preparation of high-performance electrolytes for solid-state batteries and has significant technical value and application prospects.

[0087] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing halide nanomaterials, characterized in that, Includes the following steps: Halogen raw materials were synthesized by wet ball milling and then dried. In an inert atmosphere, they were subjected to a three-stage gradient heating control, followed by cooling, crushing, and sieving to obtain halide nanomaterials with controllable size. The specific three-stage gradient heating control was as follows: the first heating stage was a low-temperature desorption stage, heating from room temperature to 120-170℃ and holding for 1-3 hours; the second heating stage was a medium-temperature crystallization stage, heating from 120-170℃ to 200-220℃ and holding for 2-4 hours; the third heating stage was a high-temperature densification stage, heating from 200-220℃ to 250-300℃ and holding for 1-2 hours. The heating rate of the first heating stage was... The heating rate of the first heating stage is less than that of the second heating stage, and the heating rate of the third heating stage is less than that of the second heating stage; the heating rate of the first heating stage is 3-8℃ / min; the heating rate of the second heating stage is 5-30℃ / min; the heating rate of the third heating stage is 3-8℃ / min; the cooling process is carried out at a rate of 1℃ / min to 3℃ / min; wherein, in the first stage: the volume concentration of inert gas is 90-92%, in the second stage: the volume concentration of inert gas is 98-98.5%, and in the third stage: the volume concentration of inert gas is 99.8-99.9%.

2. The preparation method according to claim 1, characterized in that, The wet ball milling synthesis is specifically as follows: an appropriate amount of solvent, dispersant, and weighed raw materials are added to a ball mill jar, and the ball milling reaction is carried out in a ball mill. The solvent is selected from at least one of alkane solvents, benzene solvents, ether solvents, and ketone solvents, and at least one of dichloromethane, n-heptane, n-decane, p-xylene, trimethylbenzene, anisole, monochlorobenzene, and cyclohexanone. The grinding medium during ball milling is zirconia balls with a diameter range of 0.1-10 mm.

3. A halide nanomaterial prepared by the preparation method according to any one of claims 1-2, characterized in that, The particle size D50 is ≤0.9μm, the particle size deviation is ≤5%, and it has a regular circular structure. The surface of the single crystal particles is smooth and the edges are clear. The average aspect ratio is 1:1.2-1:1.5, and there is no obvious agglomeration. The particles are uniformly distributed inside and have a mesoporous structure with a pore size of 5-10nm, which can serve as an additional ion transport channel. The packing density between particles is ≥75%.

4. An electrode characterized in that it comprises the halide nanomaterial as described in claim 3.

5. A battery characterized in that, Includes the electrode as described in claim 4.

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