Spherical sulfide solid electrolyte and preparation method and system thereof

Abstract

The invention relates to the technical field of new energy battery materials, in particular to a spherical sulfide solid electrolyte and a preparation method and system.The preparation method of the spherical sulfide solid electrolyte comprises the steps that original sulfide solid electrolyte powder is pretreated, and pretreated powder is obtained; the pretreated powder is put into a cavity provided with an arc-shaped collision plate, inert gas is introduced, shaping treatment is carried out through directional centrifugal force generated by a rotor with guide vanes, an obtained spherical sulfide solid-state electrolyte precursor is subjected to airflow grading treatment, and the spherical sulfide solid-state electrolyte is obtained. A rotor with guide vanes is used for generating directional centrifugal force, inert gas is introduced, pretreated powder is subjected to shaping treatment in a cavity with an arc-shaped collision plate, 'uniform surface contact collision 'is achieved, and meanwhile, a'parameter-performance' quantitative relation can be established by conducting linkage regulation and control on the temperature of the cavity, the rotating speed of the rotor and the flow of the inert gas.

Description

Technical Field

[0001] This invention relates to the field of new energy battery materials technology, and in particular to a spherical sulfide solid electrolyte and its preparation method and system. Background Technology

[0002] Sulfide solid electrolytes are core materials for next-generation high-safety solid-state batteries, especially Li6PS5Cl (LPSC), a typical representative of silver sulfide-germanium ore solid electrolytes, which can achieve an ionic conductivity of up to 10 at room temperature. -3 The S / cm ratio is on the order of magnitude, far exceeding that of oxide electrolytes. Spherical LPSC particles, due to their good flowability and high packing density, can significantly improve electrode mixing uniformity and interfacial contact, making them a core direction for current optimization of solid-state electrolyte morphology.

[0003] Currently, the preparation technologies for spherical sulfide solid electrolytes are mainly divided into two categories: wet processes and dry processes. However, both have intractable defects. Existing wet processes for preparing spherical sulfide solid electrolytes have problems such as: solvent residue damaging electrical properties, high energy consumption and environmental pollution, and low particle strength and easy breakage. Existing dry processes for preparing spherical sulfide solid electrolytes have problems such as: severe lattice damage, uneven sphericity and low production capacity, and equipment wear and pollution.

[0004] Current processes for preparing spherical sulfide solid electrolytes fail to achieve a balance between high sphericity, high conductivity, and scalability. Wet processes sacrifice conductivity for sphericity, while dry ball milling sacrifices both sphericity and conductivity for efficiency. Furthermore, existing equipment (such as spray dryers and ball mills) is general-purpose and not designed for the brittle and reactive characteristics of sulfide solid electrolytes, making it impossible to precisely control the shaping process. Additionally, existing technologies lack a quantitative relationship between rotational speed, temperature, time, and sphericity / conductivity, resulting in a product yield of less than 85% and hindering stable mass production.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a spherical sulfide solid electrolyte and its preparation method and system, which aims to solve the problems of solvent residue, high energy consumption, low particle strength, and easy lattice damage and poor sphericity in the existing wet preparation of spherical sulfide solid electrolytes.

[0007] The technical solution of the present invention is as follows: A method for preparing a spherical sulfide solid electrolyte, comprising the following steps: The original sulfide solid electrolyte powder was pretreated to obtain pretreated powder. The pretreated powder is fed into a cavity equipped with an arc-shaped collision plate and an inert gas is introduced. The powder is then shaped by a rotor with guide vanes generating directional centrifugal force. This yields a spherical sulfide solid electrolyte precursor. The spherical sulfide solid electrolyte precursor is subjected to airflow classification treatment to obtain the spherical sulfide solid electrolyte.

[0008] The method for preparing the spherical sulfide solid electrolyte includes a pretreatment step comprising: sieving the original sulfide solid electrolyte powder through a 150-200 mesh sieve under an inert atmosphere to obtain pretreated powder.

[0009] The method for preparing the spherical sulfide solid electrolyte includes at least six arc-shaped collision plates; the arc-shaped collision plates are spaced apart from the inner wall of the cavity and are distributed at equal intervals around the inner wall of the cavity.

[0010] The method for preparing the spherical sulfide solid electrolyte, wherein the elastic modulus of the arc-shaped collision plate is 360 GPa-380 GPa; and the elastic modulus of the guide vane is 310 GPa-340 GPa.

[0011] The method for preparing the spherical sulfide solid electrolyte includes the following: the inert gas flow rate is 5 L / min-10 L / min; the rotor speed is 1500 rpm-2500 rpm; the classifier wheel speed is 4000 rpm-6000 rpm; and the airflow velocity is 8 m / s-15 m / s.

[0012] The method for preparing the spherical sulfide solid electrolyte, wherein the temperature of the cavity is 25℃-60℃; and the shaping time is 20min-40min.

[0013] A spherical sulfide solid electrolyte is prepared using the aforementioned method for preparing spherical sulfide solid electrolytes.

[0014] A system for preparing a spherical sulfide solid electrolyte for implementing the preparation method, comprising: A housing unit, wherein the housing unit is provided with a cavity; the inner wall of the cavity is provided with a plurality of arc-shaped collision plates distributed at equal intervals; A rotor unit, comprising a rotor and guide vanes disposed on the rotor; the rotor is disposed inside the cavity; A gas delivery unit is used to deliver inert gas to the cavity; The airflow grading unit includes a multi-stage receiving bin and a pneumatic pump; the multi-stage receiving bin is connected to the cavity.

[0015] The spherical sulfide solid electrolyte preparation system further includes a drive motor located outside the cavity and connected to the rotor in the rotor unit; the guide vanes include a primary guide vane and a secondary guide vane, the size of the primary guide vane being smaller than the size of the secondary guide vane, and the secondary guide vane being disposed near the bottom of the cavity.

[0016] The preparation system for the spherical sulfide solid electrolyte further includes a cooling unit arranged around the shell unit.

[0017] Beneficial effects: This invention provides a spherical sulfide solid electrolyte and its preparation method and system. The preparation method of the spherical sulfide solid electrolyte includes the following steps: pretreating the original sulfide solid electrolyte powder to obtain pretreated powder; putting the pretreated powder into a cavity equipped with an arc-shaped collision plate and introducing inert gas, and shaping it by directional centrifugal force generated by a rotor with guide vanes to obtain a spherical sulfide solid electrolyte precursor; and performing airflow classification treatment on the spherical sulfide solid electrolyte precursor to obtain the spherical sulfide solid electrolyte. This invention utilizes a rotor with guide vanes to generate directional centrifugal force and introduces inert gas to shape pre-treated powder within a cavity equipped with an arc-shaped collision plate, achieving "uniform surface contact collision." Simultaneously, by linking and controlling the cavity temperature, rotor speed, and inert gas flow rate, a quantitative "parameter-performance" relationship can be established. Furthermore, the spherical particles achieved through dry plastic deformation do not introduce additional solvents that could cause electrolyte reactions, fundamentally solving the problem of residual functional groups from incomplete drying affecting subsequent electrolyte application in battery cells. Additionally, the controlled plastic deformation achieves "dense" spherical particles with a sphericity retention rate ≥90% after compaction, reducing electrode porosity to 15-20%. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of a method for preparing a spherical sulfide solid electrolyte according to the present invention. Figure 2 This is a schematic diagram of a system for preparing a spherical sulfide solid electrolyte to implement the preparation method described above. Figure 3 This is a top view of the cavity; Figure 4 The image shown is the XRD pattern of LPSC after spherical processing in Example 1. Figure 5 SEM images of the spherical deformation before and after preparation; Figure 6 Particle size distribution of spherical LPSCs after shaping treatment; Explanation of reference numerals in the attached drawings: 10 housing unit, 11 cavity, 12 arc-shaped collision plate, 13 air inlet, 20 rotor unit, 21 rotor, 22 guide vane, 221 primary guide vane, 222 secondary guide vane, 23 drive motor, 30 airflow classification unit, 31 multi-stage collection bin, 311 primary collection bin, 312 secondary collection bin, 313 tertiary collection bin, 32 pneumatic pump, 40 cooling unit, 41 water inlet, 42 water outlet, 50 feeding unit, 51 spiral feed inlet, 60 base plate, 70 control panel. Detailed Implementation

[0019] This invention provides a method and system for preparing spherical sulfide solid electrolytes. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0021] The existing wet process is the mainstream method for producing spherical sulfide solid electrolytes. Its core principle is "solvent dispersion - spray drying / precipitation shaping." The specific process involves dispersing sulfide solid electrolyte powder in solvents such as ethanol and N-methylpyrrolidone, adding dispersants such as polyvinylpyrrolidone (PVP), and then spray drying (inlet temperature 120-180℃, outlet temperature 60-80℃) or anti-solvent precipitation (e.g., adding water as an anti-solvent) to form spherical particles. Finally, the solvent is removed by vacuum drying (80-120℃, 12-24h). However, this method has drawbacks, including: sulfide solid electrolytes readily react with polar solvents (such as NMP and water), leading to an ionic conductivity loss >20% (from 1.0 × 10⁻⁶). -3 S / cm decreased to <8.0×10 -4 In addition, the residual solution can have various unspeakable negative effects on the subsequent application of electrolytes; spray drying requires continuous high temperature, with a unit energy consumption of 1.5 kW・h / kg, far exceeding the dry process; solvent recovery requires additional equipment, and the volatilization of solvents such as NMP will cause air pollution, increasing environmental treatment costs by 20%; the spherical particles formed by wet process are "agglomerated" (formed by the bonding of nano-scale fine powders), which are easily broken during the compaction process, and the sphericity drops from 0.8 after spray drying to below 0.6 after electrode pressing, making it unstable for application.

[0022] Existing dry processes primarily rely on "ball milling shaping," which includes planetary ball milling and stirred ball milling. The principle involves shaping the sulfide solid electrolyte particles through the impact and crushing of the grinding media (agate balls, corundum balls). However, this method has drawbacks, including: the impact force between the grinding media and particles reaches 50-100N during ball milling, causing cracks in the sulfide solid electrolyte lattice and resulting in a conductivity retention rate of <50%; ball milling relies on "random collisions," easily leading to "flattened" and "multi-faceted" particles (sphericity ≤0.75), and a single batch throughput of <10kg, which cannot meet mass production requirements (solid-state battery production lines require a single batch throughput of ≥50kg); equipment wear and contamination: long-term impact of the grinding media generates metal / ceramic debris (such as Fe). 3+ Al 3+ Zr 2+ Impurities with a content greater than 15 ppm result in a 30% reduction in battery cycle life.

[0023] Based on this, such as Figure 1 As shown, this invention provides a method for preparing a spherical sulfide solid electrolyte, comprising the following steps: Step S10: Pre-treat the original sulfide solid electrolyte powder to obtain pre-treated powder; Step S20: The pretreated powder is put into a cavity equipped with an arc-shaped collision plate and an inert gas is introduced. The powder is then shaped by a rotor with guide vanes generating directional centrifugal force to obtain a spherical sulfide solid electrolyte precursor. Step S30: Perform airflow classification treatment on the spherical sulfide solid electrolyte precursor to obtain spherical sulfide solid electrolyte.

[0024] In this embodiment, a rotor with guide vanes generates directional centrifugal force and introduces inert gas to shape the pretreated powder in a cavity equipped with an arc-shaped collision plate, achieving "uniform surface contact collision". Simultaneously, the cavity temperature, rotor speed, and inert gas flow rate can be linked and controlled to establish a quantitative relationship between parameters and performance. Furthermore, the spherical particles achieved through dry plastic deformation do not introduce additional solvents that could cause electrolyte reactions, fundamentally solving the problem that residual functional groups from incomplete drying can affect the subsequent application of electrolytes to the battery cell. Additionally, "dense" spherical particles are achieved through controllable plastic deformation, with a sphericity retention rate ≥90% after compaction, and electrode porosity reduced to 15-20%.

[0025] Specifically, the guide vanes on the rotor act as "adjusters" for the trajectory of the pretreated powder particles. The rotor with guide vanes generates directional centrifugal force, forcing the sulfide solid electrolyte particles to move tangentially along the cavity wall. The guide vanes control the trajectory deviation of the pretreated powder particles within ±5°, avoiding uneven local stress caused by disordered particle collisions in traditional processes. This regular motion path provides consistent initial conditions for subsequent uniform particle shaping. Furthermore, the arc-shaped collision plate avoids excessive local stress caused by "point contact" (preventing particle breakage) and gradually eliminates sharp edges through controllable plastic deformation. Simultaneously, the arc-shaped collision plate ensures uniform shaping of the particles in all directions, ultimately forming spherical shapes. In addition, by introducing inert gas into the cavity and controlling the cavity temperature, the structural integrity and electrical stability of the particles during spheroidization are ensured. Therefore, the above structural design does not exist in isolation, but through a process closed loop of "trajectory regularization - symmetric shaping - environmental protection", the structural parameters are transformed into controllable sphericity process conditions, and finally the spherical sulfide solid electrolyte with sphericity ≥0.85 and conductivity retention ≥90% is prepared.

[0026] In some embodiments, the pretreatment step includes: sieving the original sulfide solid electrolyte powder through a 150-200 mesh sieve under an inert atmosphere to obtain pretreated powder. The original powder has a particle size between 1 μm and 10 μm and a conductivity ≥ 1.0 × 10⁻⁶. -3 S / cm, after sieving, can remove agglomerated particles and obtain pretreated powder with uniform particle size.

[0027] In a preferred embodiment, the original sulfide solid electrolyte powder is sieved through a 150-mesh sieve under an inert atmosphere (Ar, purity ≥99.999%) to obtain a pretreated powder.

[0028] In some embodiments, the arc-shaped collision plates include at least six pieces; the arc-shaped collision plates are spaced apart from the inner wall of the cavity and are evenly distributed around the inner wall of the cavity. This is mainly used to make the particle trajectory inside the cavity more varied, and to make the overall spherical processing more uniform. Preferably, there are six arc-shaped collision plates, the gap between the six arc-shaped collision plates is 60°, and all are placed perpendicular to the line drawn from the center of the circle.

[0029] In some embodiments, the elastic modulus of the arc-shaped collision plate is 360 GPa-380 GPa; the elastic modulus of the guide vane is 310 GPa-340 GPa.

[0030] In a preferred embodiment, the arc-shaped collision plate is made of 99% alumina ceramic (hardness HRA92, elastic modulus of 380Gpa), ensuring wear resistance and a service life of more than 500 batches. It also has an elastic modulus close to that of LPSC, thus avoiding particle breakage due to excessive stiffness differences during collision.

[0031] In a preferred embodiment, the guide vane is made of silicon nitride ceramic with a stiffness of 310 GPa, which is close to the elastic modulus of LPSC (350 GPa), thus avoiding particle breakage due to excessive stiffness difference during collision.

[0032] In some embodiments, the sulfide solid electrolyte includes, but is not limited to, Li7PS6, Li 5.5 PS 4.5 Cl 1.5 Li 5.7 PS 4.7 Cl 1.7 One or more of Li6PS5Cl, but the cards used for comparison are all 34-0688 (Li7PS6); preferably, the sulfide solid electrolyte is Li6PS5Cl (LPSC) with an elastic modulus of 350 GPa.

[0033] Specifically, the evenly distributed arc-shaped collision plates on the inner wall of the cavity, with a structure matching the curvature of the inner wall and a material with an elastic modulus close to that of the sulfide solid electrolyte, can achieve "surface contact elastic collision" of particles. The contact area during particle impact is ≥30%, which not only avoids excessive local stress caused by "point contact" (preventing particle breakage), but also gradually eliminates sharp edges through controllable plastic deformation. Furthermore, the circumferentially evenly distributed arrangement of the 6 arc-shaped collision plates ensures that the particles undergo 6 symmetrical collisions per rotation, ensuring uniform shaping of the particles in all directions and ultimately forming a sphere.

[0034] In some embodiments, the inert gas flow rate is 5 L / min-10 L / min; the rotor speed is 1500 rpm-2500 rpm; the classifying wheel speed of the airflow classification process is 4000 rpm-6000 rpm; and the airflow velocity of the airflow classification process is 8 m / s-15 m / s. When the rotor speed is below 1500 rpm, the centrifugal force is insufficient to shape the particles; when the rotor speed is above 2500 rpm, the particles are easily broken. If the classifying wheel speed of the airflow classification process is too low, particles larger than 8 μm cannot be separated; if it is too high, fine powder with a particle size smaller than 2 μm will be mistakenly screened out.

[0035] In some embodiments, the temperature of the cavity is 25℃-60℃; the shaping treatment time is 20min-40min. When the cavity temperature is below 25℃, the sulfide solid electrolyte is brittle and easily broken upon impact; when the cavity temperature is above 60℃, ion diffusion intensifies, leading to lattice distortion. Controlling the shaping treatment time between 20min and 40min allows the sulfide solid electrolyte to be fully shaped; less than 20min results in insufficient shaping; more than 40min leads to excessive particle friction, resulting in an increase in fine powder.

[0036] Specifically, this invention controls the temperature within the cavity between 30℃ and 60℃ to prevent lattice distortion of the sulfide solid electrolyte caused by heat generated from particle collisions and friction. Simultaneously introducing high-purity inert gas (oxygen content < 5ppm) creates an inert atmosphere, preventing particle oxidation or moisture absorption. Both factors work together to ensure the structural integrity and electrical stability of the particles during spheroidization. Controlling the rotor speed between 1500rpm and 2500rpm generates sufficient centrifugal force to cause the particles to move along the cavity wall and undergo multiple elastic collisions (contact force 5-10N) with the arc-shaped collision plate, thus achieving plastic deformation under controlled temperature conditions of 25℃-60℃. Controlling the speed of the classifying wheel in the airflow classification process between 4000rpm and 6000rpm, and the airflow velocity between 8m / s and 15m / s, allows for the collection of particles with a diameter between 2μm and 8μm, resulting in spherical sulfide solid electrolytes. Through orthogonal experiments, it was verified that the finished product qualification rate within this parameter range is ≥95%, which is much higher than <85% of the existing technology.

[0037] In this embodiment, a quantitative relationship between parameters and performance is established for the first time. The rotor's high-speed rotation generates a centrifugal force of 200-500G, causing the particles to move closely against the inner wall of the cavity. Guided by the guide vanes, they impact the arc-shaped collision plate at a speed of 5-10 m / s. The stress generated by the collision (50-100 MPa) just reaches the yield strength (80 MPa) of the sulfide solid electrolyte, causing controllable plastic deformation of the particles (0.1 μm-0.3 μm deformation per collision). Each rotation of the particles involves three symmetrical collisions, gradually "polishing" them from an irregular shape into a spherical shape. For example, at a rotation speed of 2000 rpm and a temperature of 50°C, the sphericity reaches 0.88, and the conductivity is retained at 96%.

[0038] In a preferred embodiment, the classifying wheel of the airflow classification process rotates at 5500 rpm, and the airflow velocity is 10 m / s. Different particle sizes are separated by centrifugal force to ensure a uniform particle size distribution in the finished product, preventing small particles from clogging electrode pores and large particles from affecting interfacial contact. The classification process is carried out in a sealed Ar pipeline to prevent particles from contacting air. Particles between 2 μm and 8 μm (D50 = 4-5 μm) are collected; particles > 8 μm are returned to the mechanical fusion equipment for secondary processing; and fine powder < 2 μm is recycled as a byproduct.

[0039] In addition, the present invention also provides a spherical sulfide solid electrolyte, which is prepared by the method for preparing the spherical sulfide solid electrolyte.

[0040] In this embodiment, the spherical sulfide solid electrolyte obtained by this preparation method has a sphericity ≥0.85, a particle size variation coefficient ≤12%, and a room temperature conductivity ≥9.5×10⁻⁶. -4 The particle size distribution is S / cm (retention rate ≥95%), the particles are "dense" (density ≥92%), and the sphericity retention rate after tapping is ≥90%. Furthermore, this preparation method has cost advantages, with unit energy consumption reduced to 0.5 kW・h / kg (66% lower than the wet method), no solvent pollution, single batch capacity ≥100kg (10 times higher than the existing dry method), and overall cost reduction of 35%. At the same time, through clear parameter control, the product qualification rate is ≥95%, which can be adapted to the continuous production line of solid-state batteries.

[0041] In some embodiments, the sphericity of the spherical sulfide solid electrolyte is ≥0.85; the particle size of the spherical sulfide solid electrolyte is 2μm-8μm.

[0042] In addition, such as Figure 2 and Figure 3 As shown, the present invention also provides a system for preparing a spherical sulfide solid electrolyte for implementing the preparation method, comprising: The housing unit 10 has a cavity 11; the inner wall of the cavity 11 is provided with a plurality of arc-shaped collision plates 12 distributed at equal intervals. Rotor unit 20, the rotor unit 20 includes rotor 21 and guide vanes 22 disposed on rotor 21; rotor 21 is disposed inside cavity 11; A gas delivery unit is used to deliver inert gas to the cavity 11; The airflow classification unit 30 includes a multi-stage receiving hopper 31 and a pneumatic pump 32; the multi-stage receiving hopper 31 is connected to the cavity 11.

[0043] In this embodiment, by matching the curvature of the arc-shaped collision plate with the cavity (inner diameter 400-600mm) and guiding the trajectory with guide vanes, "uniform surface contact collision" is achieved, solving the problem of uneven shaping caused by the "random point contact" of existing ball mills. By using a rotor with guide vanes to generate directional centrifugal force and introducing inert gas, the pre-treated powder is shaped in the cavity equipped with the arc-shaped collision plate, achieving "uniform surface contact collision". At the same time, the cavity temperature, rotor speed and inert gas flow rate can be linked and controlled to establish a quantitative relationship between "parameters and performance". Furthermore, the spherical particles achieved by dry plastic deformation do not introduce additional solvents that would cause electrolyte reactions, fundamentally solving the problem that residual functional groups from incomplete drying would affect the subsequent application of electrolytes to the battery cell.

[0044] In some embodiments, the rotor unit 20 further includes a drive motor 23 located outside the cavity 11 and connected to the rotor 21; the guide vane 22 includes a primary guide vane 221 and a secondary guide vane 222, wherein the size of the primary guide vane 221 is smaller than the size of the secondary guide vane 222, and the secondary guide vane 222 is disposed near the bottom of the cavity 11. Preferably, both the primary guide vane 221 and the secondary guide vane 222 include eight arc-shaped guide vanes for changing the trajectory of the particles.

[0045] In some embodiments, the preparation system for the spherical sulfide solid electrolyte further includes a cooling unit 40 surrounding the shell unit 10. Deionized water is typically used as the coolant, which saves costs and prevents scale buildup due to impurities. The coolant temperature is maintained between 10-20°C, and the temperature is adjusted according to the winter and summer temperatures to ensure the reaction chamber temperature remains stable between 25-60°C.

[0046] In some embodiments, the cooling unit 40 is provided with a water inlet 41 and a water outlet 42 for the cooling pipe; adopting a bottom-inlet and top-outlet water pattern improves cooling efficiency.

[0047] In some embodiments, the preparation system for the spherical sulfide solid electrolyte further includes a feeding unit 50 connected to the shell unit 10 via a spiral feed port 51. This feeding unit can be detached and fed in an inert gas (such as argon) environment, adding 5-10 kg of powder each time. Too little powder will result in insufficient mixing, while adding too much at once will reduce the spherical preparation effect. Preferably, the feeding unit adds 5 kg. The spiral feed port 51 allows the initial material to be slowly added into the container cavity at a feeding rate of 1 kg / min, with slow rotation to ensure that the initial material does not accumulate.

[0048] In a preferred embodiment, the housing unit 10 is a stainless steel shell made of 316 stainless steel.

[0049] In some embodiments, the cavity 11 is made of a zirconium oxide layer to prevent the introduction of metallic foreign objects.

[0050] In some embodiments, a base plate 60 made of zirconium oxide is provided between the housing unit 10 and the airflow classification unit 30, which can be opened from the middle downwards to pour out the processed spherical particles.

[0051] In some embodiments, the multi-stage receiving bin 31 includes a primary receiving bin 311 near one end of the base plate 60, a secondary receiving bin 312 and a tertiary receiving bin 313 sequentially arranged at the end of the primary receiving bin 311 away from the base plate 60; the primary receiving bin 311 is used to receive larger particles or incompletely processed particles for secondary processing, mainly screening particles >8μm; the secondary receiving bin 312 is used to receive fully processed spherical particles with a particle size between 2μm and 8μm; the tertiary receiving bin 313 is used to collect particles with a particle size less than 2μm for recycling as by-products.

[0052] In some embodiments, the pneumatic pump 32 is connected to the three-stage receiving hopper 313.

[0053] In some embodiments, the housing unit 10 is provided with an air inlet 13, through which the gas supply unit delivers inert gas to the cavity 11. Before the equipment begins processing, the gas inside needs to be replaced with an inert gas, which can be nitrogen or argon; preferably, argon is selected.

[0054] In some embodiments, the preparation system for the spherical sulfide solid electrolyte further includes a control panel 70 for controlling the feed rate, the bottom plate switch, the rotor rotation speed, the pneumatic pump speed, and the temperature of the cooling unit.

[0055] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention.

[0056] Example 1 This embodiment describes the preparation method of Li using spherical sulfide solid electrolyte. 5.5 PS 4.5 Cl 1.5 The material underwent shaping treatment, and the phases before and after the treatment were compared to see if they conformed to the PDF comparison card standard, as detailed below: 1. Raw material pretreatment Raw material requirements: The raw LPSC powder must meet the following requirements: no impurity peaks in XRD (corresponding to PDF#34-0688), and metal impurity content <10ppm; Operating details: Sieve in an Ar gas glove box (oxygen content <1ppm, water content <1ppm) with stainless steel screen (to avoid slag falling from plastic screens), and collect the undersize material (particle size 3-5μm) as pre-treatment powder. Principle: Remove agglomerated particles larger than 10μm to prevent the agglomerates from being unable to be shaped during subsequent fusion, which would result in uneven sphericity of the finished product.

[0057] 2. Adopt Figure 2 The system shown performs shaping treatment on the pretreated raw materials, wherein the rotor speed is 2000 rpm, the cavity temperature is 40℃, the shaping treatment time is 40 min, the classifying wheel speed is 5500 rpm, and the airflow velocity of the airflow classification treatment is 10 m / s.

[0058] The specific steps for XRD are as follows: 1. Sample preparation Powder Sample Preparation Grinding requirements: The sulfide powder must be ground to a uniform particle size (passing through a 200-mesh sieve, particle size ≤75μm), with no grainy feel to the touch, similar to the texture of flour, in order to reduce preferred orientation and enhance the intensity of diffraction peaks.

[0059] Moisture-proof treatment: Sulfides are prone to moisture absorption and decomposition, so they need to be ground and pressed in an inert gas (such as argon) glove box to avoid oxidation or structural damage.

[0060] Compressing method: The positive pressure method is used to fill the powder into the groove of the glass sample holder and compact it with a glass plate until the surface is flat and flush with the groove to ensure sample uniformity.

[0061] 2. Instrument Setup and Testing Procedure Instrument initialization Circulating water system: Ensure water temperature is 17-20℃ and water pressure is 0.3-0.4MPa to prevent equipment from overheating or being damaged.

[0062] Software startup: Open the PC-based XRD control software (such as Rigaku Ultimate IV or DIFFRAC measurement system), initialize the goniometer, and confirm that the sample chamber door is closed.

[0063] Parameter settings Scanning range: standard wide-angle test range 5°-90°, step size 0.02°, scanning speed 5° / min (adjusted according to sample crystallinity).

[0064] Slit width: entrance slit 0.2-0.6mm, detector slit 3-8mm, optimizing resolution and signal-to-noise ratio.

[0065] X-ray conditions: copper target Kα rays (λ=1.5418 Å), voltage 40 kV, current 30 mA, to ensure clear diffraction peaks.

[0066] Sample loading and testing Sample loading procedure: Gently open the sample chamber door, insert the sample holder into the slot, ensuring the sample surface is facing up and centered, gently close the door and confirm that the closing indicator light is on.

[0067] Start the test: Click "Start" to begin the scan. Wait for the software to complete and save the data (e.g., RAW or TXT format). The XRD results are as follows: Figure 4 As shown, the phase after spherical treatment still conforms to the PDF comparison card standard.

[0068] Example 2 This embodiment describes the microscopic characterization of spherical LPSCs before and after the treatment in Example 1. The specific procedures are as follows: I. Preparations before operation (10-15 minutes) 1. Environmental Inspection Ensure the laboratory temperature is 18-25℃ and the humidity is ≤60%RH, and keep it away from vibration sources (such as centrifuges) and strong electromagnetic interference.

[0069] Check the stability of the equipment power supply and use a UPS power supply to prevent voltage fluctuations.

[0070] 2. Equipment status confirmation Check the vacuum system: the mechanical pump oil level is above the mark, and the molecular pump has no abnormal noise.

[0071] Check that the cooling water circulation is normal and the water temperature is stable (usually set at 20-25℃).

[0072] Check the condition of the electron gun filament (e.g., the tungsten filament has a lifespan of about 100-200 hours and needs to be replaced promptly).

[0073] 3. Sample pretreatment Non-conductive samples (ceramics, solid electrolytes): sputter-coated with gold (thickness 10-50nm).

[0074] Powder sample: dispersed in conductive adhesive, and fixed with a small amount of adhesive to prevent it from being scattered by electron beam bombardment.

[0075] II. Equipment Start-up and Vacuum Preparation (15-30 minutes) 1. Power-on sequence Turn on the circulating water machine → Start the mechanical pump → Wait for the mechanical pump to stabilize (about 5 minutes) → Start the molecular pump.

[0076] Press the buttons on the equipment panel: red button to power on → yellow button to start the vacuum system → after 30 seconds, press the green button to start the entire machine, and the computer will automatically enter the control software (such as SmartSEM).

[0077] 2. Vacuum pumping Open the sample chamber and place the sample inside (secure it with conductive adhesive to ensure good electrical contact with the sample stage).

[0078] Close the sample chamber, start the vacuuming process, and wait for the vacuum level to reach <8×10⁻⁶. -5 mbar (requirements may vary depending on the equipment).

[0079] Once the vacuum level is reached, the system will display "Vac Status=Ready" before proceeding to the next step.

[0080] III. Parameter Settings and Image Optimization (20-30 minutes) 1. Initialization of basic parameters Accelerating voltage (EHT): Select according to sample type (e.g., 1-30kV). Use low voltage (5-10kV) to observe surface details, and high voltage is suitable for deep structures.

[0081] Working distance (WD): Usually set to 5-10mm. Shorter distances can improve resolution, but reduce depth of field.

[0082] Beam size: High beam (e.g., 10) -9 A) Suitable for EDS analysis, low beam current (10 -12 A) Reduce sample damage.

[0083] 2. Focusing and Coordination Adjust the brightness (fixed at 50%) and contrast at low magnification (e.g., 500x) to make the image appropriately bright and dark.

[0084] Magnify to 5000x or higher and fine-tune the focus to ensure sharp edges. If the image is blurry, perform objective aperture alignment and astigmatism correction.

[0085] Check filament saturation: Slowly adjust the filament current until the image brightness no longer increases and there is no flickering.

[0086] 3. Detector selection Secondary electron (SE) detector: used for surface morphology observation, with high resolution.

[0087] Backscattered electron (BSE) detector: reflects differences in atomic number of the sample, suitable for composition analysis.

[0088] IV. Image Acquisition and Data Recording (10-20 minutes) 1. Data Acquisition Parameter Settings Scan speed: Select a slower speed (e.g., Speed=9) to reduce noise; use a fast scan for preview.

[0089] Resolution: Set according to your needs (e.g., 1024×768 or 2048×1536 pixels).

[0090] Cumulative scanning: For low-contrast samples, multiple scans can be superimposed to improve the signal-to-noise ratio.

[0091] 2. Multi-regional observation Move the sample stage, select 3-5 representative areas, and record parameters such as magnification, working distance, and detector type.

[0092] 3. Data storage Save the image as TIFF or BMP format (lossless compression) to avoid the loss of detail caused by JPEG compression.

[0093] Export the parameter file (including accelerating voltage, beam current, etc.) to facilitate subsequent analysis and tracing.

[0094] Use a dedicated USB flash drive or CD to copy data; do not insert personal storage devices into the computer.

[0095] V. Equipment maintenance and shutdown (10-15 minutes) 1. Shutdown process Shut down the electron gun and wait for the filament to cool down (about 5 minutes).

[0096] Release the gas from the sample chamber, remove the sample, and then evacuate the vacuum chamber again to standby mode.

[0097] Shut down the software, computer, molecular pump, mechanical pump, and circulating water machine in that order.

[0098] SEM images of the spherical deformation before and after preparation are shown below. Figure 5 As shown, a significant change in sphericity can be clearly observed.

[0099] Example 3 Using the same treatment method as in Example 1, the ionic conductivity of the original LPSC sample and spherical LPSCs treated for different times was tested. The specific test methods and results are as follows: 1. Sample preparation The sulfide electrolyte powder is cold-pressed into sheets under pressure of 360–500 MPa, typically 400 MPa, with a thickness of approximately 0.1–1 mm, typically 0.5 mm, and a diameter of 10–14 mm, typically 10 mm. The thickness is measured using a micrometer.

[0100] 2. Electrochemical Impedance Testing (EIS) The sample is held in place using a blocking electrode (such as stainless steel or sputtered metal film), and an AC voltage (amplitude 10mV, frequency range 1MHz to 0.1Hz) is applied.

[0101] The bulk resistance Rbulk is obtained by fitting the semicircular intercept in the high-frequency region using EIS, while the low-frequency region reflects the interfacial resistance and the double-layer effect.

[0102] 3. Geometric parameter measurement Thickness (LL): The thickness of the compressed tablet is measured directly using a micrometer; Area (AA): Calculated based on the electrode diameter; The ionic conductivity of the corresponding material can be calculated using the formula.

[0103] The sphericity is calculated as follows: Fast calculation based on 2D projection Two-dimensional electron microscope images (such as SEM images) of particles can be obtained, and the "area (A)" and "perimeter (P)" of the particle projection can be extracted using ImageJ image analysis software and substituted into the corresponding formulas for calculation.

[0104] Calculation logic: Area-perimeter method ψ = 4πA / P 2 - A: Actual area of ​​the two-dimensional projection of the particle (unit: μm) 2 ) - P: Actual perimeter of the particle's two-dimensional projection (unit: μm)

[0105] The ionic conductivity data above show that the final ionic conductivity retention rate after spherical treatment is still over 90%, and the sphericity can reach over 0.8.

[0106] Example 4 The particle size of the spherical LPSCs from Example 1, after undergoing shaping treatment, was measured using a dry sampler. The specific procedure is as follows: 1. Sample preparation: Clean the sample cell and stage, and use a special funnel to evenly fill the graduated cylinder with the sample, avoiding air bubbles or accumulation.

[0107] Connect the vacuum cleaner to ensure that dust is removed promptly.

[0108] 2. Background measurement: Click "Start Background Measurement" and wait for the instrument to stabilize before ending the measurement (background noise must be below the set threshold).

[0109] 3. Start the test: Click "Start Test" to observe the change in occlusion. If the occlusion is too high / low, adjust the injection speed or interval.

[0110] The test usually lasts 1-3 minutes until the data stabilizes.

[0111] Results output: Particle size distribution curve, D10 / D50 / D90 values, and residual analysis. The residuals must be less than the theoretical values ​​to ensure fitting accuracy.

[0112] The result is as follows Figure 6 As shown, its particle size distribution is between 2μm and 8μm.

[0113] In summary, the present invention provides a spherical sulfide solid electrolyte and its preparation method and system. The preparation method of the spherical sulfide solid electrolyte includes the following steps: pretreating the original sulfide solid electrolyte powder to obtain pretreated powder; putting the pretreated powder into a cavity equipped with an arc-shaped collision plate and introducing inert gas, and shaping it by directional centrifugal force generated by a rotor with guide vanes to obtain a spherical sulfide solid electrolyte precursor; and performing airflow classification treatment on the spherical sulfide solid electrolyte precursor to obtain the spherical sulfide solid electrolyte. This invention utilizes a rotor with guide vanes to generate directional centrifugal force and introduces inert gas to shape pre-treated powder within a cavity equipped with an arc-shaped collision plate, achieving "uniform surface contact collision." Simultaneously, by linking and controlling the cavity temperature, rotor speed, and inert gas flow rate, a quantitative "parameter-performance" relationship can be established. Furthermore, the spherical particles achieved through dry plastic deformation do not introduce additional solvents that could cause electrolyte reactions, fundamentally solving the problem of residual functional groups from incomplete drying affecting subsequent electrolyte application in battery cells. Additionally, the controlled plastic deformation achieves "dense" spherical particles with a sphericity retention rate ≥90% after compaction, reducing electrode porosity to 15-20%.

[0114] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for producing a spherical sulfide solid-state electrolyte, characterized by, The method comprises the steps of: pretreating an original sulfide solid electrolyte powder to obtain a pretreated powder; putting the pretreated powder into a cavity provided with arc-shaped collision plates and feeding inert gas, shaping the powder by a rotor with guide vanes to generate directional centrifugal force, to obtain a spherical sulfide solid electrolyte precursor; airflow classifying the spherical sulfide solid electrolyte precursor to obtain a spherical sulfide solid electrolyte.

2. The method of producing a spherical sulfide solid-state electrolyte according to claim 1, characterized by, The pretreating step comprises: sieving the original sulfide solid electrolyte powder through a 150-mesh-200-mesh sieve under an inert atmosphere to obtain the pretreated powder.

3. The method of producing a spherical sulfide solid-state electrolyte according to claim 1, characterized by, The arc-shaped collision plates comprise at least six plates; the arc-shaped collision plates are arranged at intervals around the inner wall of the cavity and are distributed at equal intervals around the inner wall of the cavity.

4. The method of producing a spherical sulfide solid-state electrolyte according to claim 1, characterized by, The elastic modulus of the arc-shaped collision plates is 360 Gpa-380 Gpa; the elastic modulus of the guide vanes is 310 Gpa-340 Gpa.

5. The method of producing a spherical sulfide solid-state electrolyte according to claim 1, characterized by, The gas flow of the inert gas is 5 L / min-10 L / min; the rotation speed of the rotor is 1500 rpm-2500 rpm; the rotation speed of the classification wheel of the airflow classification is 4000 rpm-6000 rpm, and the airflow speed of the airflow classification is 8 m / s-15 m / s.

6. The method of producing a spherical sulfide solid-state electrolyte according to claim 1, characterized by, The temperature of the cavity is 25℃-60℃; the time of the shaping treatment is 20 min-40 min.

7. A spherical sulfide solid-state electrolyte characterized by, The spherical sulfide solid electrolyte is prepared by the method according to any one of claims 1-6.

8. A system for producing a spherical sulfide solid-state electrolyte for implementing the production method according to any one of claims 1 to 6, characterized in that, The method comprises the steps of: a housing unit provided with a cavity; the inner wall of the cavity is provided with arc-shaped collision plates distributed at equal intervals; a rotor unit comprising a rotor and guide vanes arranged on the rotor; the rotor is arranged inside the cavity; a gas feeding unit for feeding inert gas to the cavity; an airflow classification unit comprising a multistage collection bucket and a pneumatic pump; the multistage collection bucket is in communication with the cavity.

9. The system for preparing a spherical sulfide solid-state electrolyte according to claim 8, characterized by, The rotor unit further comprises a driving motor located outside the cavity and connected to the rotor; the guide vanes comprise primary guide vanes and secondary guide vanes; the size of the primary guide vanes is smaller than that of the secondary guide vanes, and the secondary guide vanes are arranged close to the bottom of the cavity.

10. The system for preparing a spherical sulfide solid-state electrolyte of claim 8, wherein, The preparation system of the spherical sulfide solid electrolyte further comprises a cooling unit arranged around the housing unit.

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