Composite solid electrolyte particles, and methods of making and using the same

Abstract

The application provides a kind of composite solid electrolyte particles and its preparation method and application, the composite solid electrolyte particles are core-shell structure, the core layer of the core-shell structure includes inorganic solid electrolyte, the shell layer of the core-shell structure includes organic component, with the inorganic solid electrolyte as core layer, the organic component is coated on its outside as shell layer, can be comprehensive inorganic solid electrolyte and organic component both sides of advantage, reach the effect of playing to one's strengths and avoiding one's weaknesses, so that the composite solid electrolyte particles obtained simultaneously have higher mechanical properties, higher stability and higher ionic conductance characteristics, applied in solid-state battery helps to improve the interface problem between electrolyte and positive and negative electrode in the solid-state battery, and then helps to improve the electrical properties and safety performance of the solid-state battery.

Description

Technical Field

[0001] This invention belongs to the field of solid-state battery technology, specifically relating to a composite solid-state electrolyte particle, its preparation method, and its application. Background Technology

[0002] With continuous technological advancements, electrochemical energy storage has increasingly become an essential part of daily life, meeting people's needs in mobile transportation, large-scale energy storage, and electronic products. Lithium-ion batteries, as the most important electrochemical energy storage device, have also experienced significant development since their commercialization in 1991, with substantial improvements in cycle life, energy density, and safety. However, with increasingly stringent requirements for battery technology, existing liquid electrolyte systems still have shortcomings in energy density and safety. Side reactions of the electrolyte during battery operation, leading to volatilization and leakage, can cause irreversible capacity degradation, affecting the lifespan of lithium-ion batteries.

[0003] The emergence of solid-state batteries has effectively solved the above problems and represents the future direction for the development of high-capacity rechargeable batteries. Solid-state batteries have advantages such as high thermal stability, wide electrochemical window, fewer side reactions, high safety, and high output voltage, and are expected to replace existing liquid electrolyte battery systems. Among these, the solid electrolyte is the core of solid-state batteries, mainly including two categories: inorganic solid electrolytes and polymer solid electrolytes.

[0004] Inorganic solid electrolytes include sulfide solid electrolytes, oxide solid electrolytes, borohydride solid electrolytes, and halide solid electrolytes. Oxide solid electrolyte materials have advantages such as high safety performance, good stability, low cost, and environmental friendliness. Sulfide solid electrolytes have high ionic conductivity at room temperature, and at the same time, they have negligible electronic conductivity and good mechanical properties, which is conducive to the formation of a good solid-solid contact interface between the electrode and electrolyte in all-solid-state batteries, thereby optimizing the cycle stability of all-solid-state batteries. CN109390626A discloses an inorganic solid electrolyte synthesis process and its solid-state battery. The solid electrolyte is manufactured using an unconventional process, which modifies the composition of the material by the insertion and extraction of ions in the raw materials under ambient temperature and pressure. This process has low energy consumption and good consistency. The composition ratio of the material and the progress of the synthesis can be controlled by digital, intelligent, and automated means. The material synthesized by this method has good ionic conductivity at room temperature. When used as a solid electrolyte for lithium-ion batteries or sodium-ion batteries, the battery has a high discharge rate at room temperature, long cycle life, and good safety performance.

[0005] Polymer solid electrolytes include various polymer matrices such as polyethylene oxide (PEO) / polyacrylonitrile (PAN) and polymethyl methacrylate (PMMA), as well as polyionic liquid solid electrolytes, which have recently gained increasing research attention. CN111533851A discloses a method for preparing a polymer electrolyte by in-situ polymerization in a battery and its application in all-solid-state batteries. This polymer electrolyte comprises a polymer matrix and a lithium salt composited within the polymer matrix. The polymer electrolyte is formed by in-situ polymerization of materials including small molecule additives, crosslinking agents, and the lithium salt in the battery via thermal initiation. The small molecule additives are carbonate molecules containing olefinic unsaturated bonds, and the crosslinking agent is a substance containing polyethylene glycol acrylate structural units. This polymer electrolyte combines the high voltage resistance of carbonate polymers with the high ionic conductivity of polyethylene glycol segments.

[0006] Although both inorganic solid electrolytes and polymer solid electrolytes have their own excellent properties, they also have their own obvious shortcomings. Oxide inorganic solid electrolytes exhibit significant rigidity, resulting in point-to-point contact between particles and with electrode materials, severely impacting interparticle ion transport. Sulfide solid electrolytes have poor air stability, readily denaturing upon exposure to air and becoming inactive; they also suffer from high rigidity, hindering interparticle ion transport. Other inorganic electrolytes exhibit similar characteristics, either high rigidity, difficulty in interparticle ion transport, or poor air stability. While polymers offer good flexibility and generally good air stability, their bulk ionic conductivity is typically poor, far lower than that of inorganic electrolytes.

[0007] Based on the above problems, developing a composite solid electrolyte particle that combines the advantages of both inorganic and organic materials, and possesses high mechanical properties, high stability, and high ionic conductivity, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a composite solid electrolyte particle, its preparation method, and its application. The composite solid electrolyte particle has a core-shell structure, wherein the core layer of the core-shell structure includes an inorganic solid electrolyte, and the shell layer includes an organic component. The composite solid electrolyte particle combines the excellent properties of both inorganic solid electrolytes and organic components, possessing excellent mechanical properties, high stability, and high ionic conductivity, and is expected to provide a new development opportunity for solid-state batteries.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a composite solid electrolyte particle, wherein the composite solid electrolyte particle has a core-shell structure, and the core layer of the core-shell structure includes an inorganic solid electrolyte.

[0011] The shell of the core-shell structure includes organic components, which include organic solid electrolytes and / or polymers that do not swell in the electrolyte.

[0012] The composite solid electrolyte particles provided by this invention have a core-shell structure, with an inorganic solid electrolyte as the substrate core and an organic component coating the outside as the shell, combining the excellent properties of both organic components and inorganic solid electrolytes. Specifically, organic components with excellent mechanical properties and good stability but low conductivity are used to encapsulate inorganic solid electrolytes with poor mechanical properties (oxide solid electrolytes) or poor stability (sulfide solid electrolytes) but high conductivity. This avoids the problem of inorganic solid electrolytes being easily denatured when directly exposed to air, and also improves the ion transport effect between particles, achieving the effect of maximizing strengths and minimizing weaknesses. The resulting composite solid electrolyte particles simultaneously possess high mechanical properties, high stability, and high ionic conductivity. When applied to solid-state batteries, this helps to improve the interface problem between the electrolyte and the positive and negative electrodes, thereby helping to improve the electrical and safety performance of the solid-state battery.

[0013] In this invention, the term "polymer that does not swell in electrolyte" refers to a polymer that does not change volume in electrolyte and does not react with electrolyte. The same expressions used below have the same meaning.

[0014] Preferably, the particle size of the composite solid electrolyte particles is 10-1000 nm, such as 50 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm or 900 nm, and more preferably 30-500 nm.

[0015] As a preferred technical solution of the present invention, the particle size of the composite solid electrolyte particles is preferably 10-1000 nm, and more preferably 30-500 nm, so that the performance of the obtained composite solid electrolyte is optimal. On the one hand, if the particle size of the composite solid electrolyte particles is less than 30 nm, the specific surface area of ​​the obtained composite solid electrolyte will be too large, affecting the coating effect and making it difficult to control the coating thickness. On the other hand, if the particle size of the composite solid electrolyte particles is greater than 500 nm, the particles of the composite solid electrolyte will be too large, which will also affect the coating effect, as well as the ion conduction and system compaction density.

[0016] Preferably, the inorganic solid electrolyte includes any one or a combination of at least two of oxide solid electrolytes, sulfide solid electrolytes, or chloride solid electrolytes.

[0017] Preferably, the oxide solid electrolyte includes any one or a combination of at least two of NASICON-type oxide solid electrolytes, garnet-type oxide solid electrolytes, or perovskite-type oxide solid electrolytes.

[0018] Preferably, the NASICON-type oxide solid electrolyte includes any one or a combination of at least two of lithium titanium phosphate (LTP), lithium germanium phosphate (LGP), lithium zirconium phosphate (LZP), lithium titanium aluminum phosphate (LATP), lithium germanium aluminum phosphate (LAGP), or lithium zirconium silicon phosphate (LZSP).

[0019] Preferably, the garnet-type oxide solid electrolyte includes lithium lanthanum zirconium oxide (LLZO).

[0020] Preferably, the perovskite-type oxide solid electrolyte includes lithium lanthanum titanium oxide (LLTO).

[0021] Preferably, the sulfide solid electrolyte includes any one or a combination of at least two of Li-P-S type solid electrolytes, Li 11-n M 2-n P 1+n S 12 type solid electrolytes, or Li6PS5X type solid electrolytes,

[0022] where 0 < n ≤ 1, M is selected from Ge, Sn, or Si, and X is selected from Cl, Br, or I.

[0023] Preferably, the Li-P-S type solid electrolyte includes Li3PS4 and / or Li7P3S 11 .

[0024] Preferably, the Li 11-n M 2-n P 1+n S 12 type solid electrolyte includes Li2S-GeS2-P2S5.

[0025] Preferably, the thickness of the shell does not exceed 100 nm, such as 90 nm, 80 nm, 70 nm, 60 nm, 50 nm, 40 nm, 30 nm, 20 nm, or 10 nm, etc., and is further preferably not more than 50 nm.

[0026] As a preferred technical solution of the present invention, the thickness of the shell layer of the composite solid electrolyte particles is preferably no more than 100 nm, and more preferably no more than 50 nm, so that the performance of the obtained composite solid electrolyte is optimal. On the one hand, if the thickness of the shell layer of the composite solid electrolyte particles exceeds 50 nm, it will result in a thicker shell layer, making it difficult for the components of the core layer to exert their effects directly, thus affecting the ionic conductivity.

[0027] Preferably, the polymeric solid electrolyte includes any one or a combination of at least two of the following: ether-based polymeric solid electrolyte, cyano-based polymeric solid electrolyte, siloxane-based polymeric solid electrolyte, carbonate-based polymeric solid electrolyte, or fluorine-based polymeric solid electrolyte.

[0028] Preferably, the ether-based polymer solid electrolyte includes a polyethylene oxide solid electrolyte.

[0029] Preferably, the cyanopolymer solid electrolyte comprises a polyacrylonitrile solid electrolyte.

[0030] Preferably, the siloxane polymer solid electrolyte comprises a polymethylhydrosiloxane solid electrolyte.

[0031] Preferably, the carbonate-based polymer solid electrolyte includes a polyvinyl carbonate solid electrolyte.

[0032] Preferably, the fluorinated polymer solid electrolyte includes a polyvinylidene fluoride solid electrolyte.

[0033] Preferably, the monomer of the polyionic liquid solid electrolyte includes ionic liquid and / or grafted ionic liquid.

[0034] Preferably, the ionic liquid is composed of ionic liquid cations and ionic liquid anions.

[0035] Preferably, the grafted ionic liquid is composed of ionic liquid cations, ionic liquid anions, and grafted monomers.

[0036] Preferably, the ionic liquid cation includes [Emim]. + [Bmin] + [Cmim] + [Daim] + [Veim] + [BCNim] + , [PP 14 ] + [Pyr] 13 ] + 、[N 111 ] + [DEME] + or [P] 111i4 ]+ Any one or at least two of them.

[0037] Preferably, the ionic liquid anion includes [BF4]. - [N(CN)2]2 - [CH3COO] - [TfO] - [FSI] - Or [TFSI] - Any one or at least two of them.

[0038] Preferably, the grafting monomer comprises ethylene oxide and / or methyl methacrylate.

[0039] Preferably, the ionic liquid comprises [Pyr 13 [FSI], [Emim], [TFSI], or [PP] 14 Any one or at least two of the [TFSI] criteria.

[0040] Preferably, the grafted ionic liquid comprises PMMA-[Pyr] 13 [FSI] or PEO-[Emim][TFSI], or any combination of at least two of them.

[0041] Preferably, the polyionic liquid solid electrolyte includes any one or a combination of at least two of the following: polyimidazolium ionic liquid solid electrolyte, polypyrrole ionic liquid solid electrolyte, polypyridine ionic liquid solid electrolyte, polypiperidine ionic liquid solid electrolyte, or polyquaternary ammonium salt ionic liquid solid electrolyte.

[0042] Preferably, the polyionic liquid solid electrolyte includes P[Pyr] 13 [FSI], P[Emim][TFSI], P[PP] 14 [TFSI]、P{PMMA-[Pyr 13 [FSI]} or P{PEO-[Emim][TFSI]}, or any combination of at least two of them.

[0043] In a second aspect, the present invention provides a method for preparing composite solid electrolyte particles as described in the first aspect, the preparation method comprising method A or method B;

[0044] Method A includes: mixing the core layer and shell layer in water, spray drying, to obtain the composite solid electrolyte particles;

[0045] Method B includes: mixing the monomers of the core layer and the shell layer in water, adding a thermal initiator, and spray drying to obtain the composite solid electrolyte particles.

[0046] The preparation method of the composite solid electrolyte particles provided by this invention is simple to operate and specifically includes two methods, either Method A or Method B. Method A involves directly mixing the shell and core materials in water to form a solution, followed by spray drying. During this process, the organic solid electrolyte of the shell adheres to the surface of the core, directly yielding the core-shell structured composite electrolyte. Alternatively, Method B involves mixing the core and shell monomer materials in water to form a solution, adding a thermal initiator, and then spray drying. During spray drying, the thermal initiator initiates a thermopolymer reaction, causing the shell monomers to polymerize and coat the outside of the core, forming a core-shell structured composite solid electrolyte. Both preparation methods are simple, achieving coating in a single drying step, and have good application potential.

[0047] Preferably, in both method A and method B, the mixing process further includes a ball milling step.

[0048] Preferably, in methods A and B, the raw material supply rate for spray drying is 10–30 L / h (e.g., 13 L / h, 16 L / h, or 19 L / h, etc.), the hot air inlet temperature is 180–300°C (e.g., 200°C, 240°C, 260°C, or 280°C, etc.), and the exhaust temperature is 80–120°C (e.g., 90°C, 100°C, or 110°C, etc.).

[0049] Preferably, in method B, the thermal initiator includes any one or a combination of at least two of azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, dialkyl peroxide, cumene hydroperoxide, or tert-butyl hydroperoxide.

[0050] Thirdly, the present invention provides an application of composite solid electrolyte particles as described in the first aspect in solid-state batteries.

[0051] Preferably, the solid-state battery includes a solid-state lithium-ion battery or a solid-state sodium-ion battery.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] The composite solid electrolyte particles provided by this invention have a core-shell structure. The core layer of the core-shell structure includes an inorganic solid electrolyte, and the shell layer includes an organic component, which includes an organic solid electrolyte and / or a polymer that does not swell in the electrolyte. By using the inorganic solid electrolyte as the substrate core and the organic component as the shell layer, the excellent properties of both the organic component and the inorganic solid electrolyte are combined, achieving the effect of maximizing strengths and minimizing weaknesses. This results in composite solid electrolyte particles that simultaneously possess high mechanical properties, high stability, and high ionic conductivity. When applied to solid-state batteries, this helps to improve the interface problem between the electrolyte and the positive and negative electrodes, thereby improving the electrical and safety performance of the solid-state battery. Attached Figure Description

[0054] Figure 1 The image is a 5.00 kJ scanning electron microscope image of the composite solid electrolyte obtained in Example 1.

[0055] Figure 2 This is a 10.0 kJ scanning electron microscope image of the composite solid electrolyte obtained in Example 1. Detailed Implementation

[0056] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0057] Example 1

[0058] A composite solid electrolyte particle, wherein the composite solid electrolyte particle has a core-shell structure, a particle size of 200 nm, a core layer of lithium aluminum titanium phosphate, and a shell layer thickness of 40 nm, wherein the shell layer is composed of polyethylene oxide solid electrolyte (Sumitomo Chemicals Co., Ltd., PFZ blue) and P[Pyr] in a molar ratio of 1:1. 13 [FSI] (Shanghai Chengjie Chemical Co., Ltd.);

[0059] The preparation method of the composite solid electrolyte particles includes: mixing lithium titanium aluminum phosphate, polyethylene oxide solid electrolyte, and P[Pyr 13 [FSI] is mixed in water, ball-milled, and then spray-dried at 200°C to obtain the composite solid electrolyte particles.

[0060] Example 2

[0061] A composite solid electrolyte particle, wherein the composite solid electrolyte particle has a core-shell structure, a particle size of 500 nm, a core layer of zirconium lanthanum lithium, and a shell layer thickness of 50 nm, and the shell layer is P[Pyr 13 [FSI] (Shanghai Chengjie Chemical Co., Ltd.);

[0062] The preparation method of the composite solid electrolyte particles includes: mixing zirconium oxide, lithium lanthanum, and P[Pyr 13 [FSI] and water are mixed, ball-milled, and then spray-dried at 200°C to obtain the composite solid electrolyte particles.

[0063] Example 3

[0064] A composite solid electrolyte particle, wherein the composite solid electrolyte particle has a core-shell structure, a particle size of 30 nm, a core layer of Li3PS4, a shell layer thickness of 10 nm, and a shell layer of polyethylene oxide solid electrolyte.

[0065] The preparation method of the composite solid electrolyte particles includes: mixing Li3PS4 and ethylene oxide in water, adding azobisisobutyronitrile, ball milling, and spray drying at 200°C to obtain the composite solid electrolyte particles.

[0066] Examples 4-5

[0067] A composite solid electrolyte particle, which differs from Example 1 only in that the particle sizes of the composite solid electrolyte particles are 800 nm and 10 nm, respectively, while the other structures, parameters and preparation methods are the same as those in Example 1.

[0068] Examples 6-7

[0069] A composite solid electrolyte particle, which differs from Example 1 only in that the thickness of the shell is 80 and 110 nm respectively, while the other structures, parameters and preparation methods are the same as those in Example 1.

[0070] Example 8

[0071] A composite solid electrolyte particle, wherein the composite solid electrolyte particle has a core-shell structure, a particle size of 150 nm, a core layer of lithium aluminum titanium phosphate, a shell layer thickness of 30 nm, and a shell layer of PTFE (Aladdin Reagent (Shanghai) Co., Ltd., P110094), and its preparation method is the same as that in Example 1.

[0072] Comparative Example 1

[0073] A polymer solid electrolyte particle with a particle size of 200 nm is composed of polyethylene oxide (Sumitomo Chemical Co., Ltd., PFZ blue) and P[Pyr] in a molar ratio of 1:1. 13 [FSI] (Shanghai Chengjie Chemical Co., Ltd.) composition;

[0074] Its preparation method includes: mixing polyethylene oxide and P[Pyr 13 [FSI] is mixed in water, ball-milled, and then spray-dried at 200°C to obtain the polymer solid electrolyte particles.

[0075] Comparative Example 2

[0076] An oxide solid electrolyte particle with a particle size of 200 nm, made of lithium titanium aluminum phosphate.

[0077] Application Example 1

[0078] A lithium-ion battery comprising a positive electrode, a negative electrode, and a fibrous composite solid electrolyte obtained in Example 1;

[0079] The manufacturing process of the lithium-ion battery includes the following steps:

[0080] (1) Using lithium metal foil as the negative electrode active material, it is punched and cut to make a negative electrode sheet;

[0081] (2) Using NCM811 material as positive electrode active material, CNT as conductive agent, and PVDF as binder, PVDF is dissolved in NMP to obtain adhesive solution. The above materials are homogenized in a planetary mixer at a mass ratio of 97.5:1:1.5 to obtain positive electrode active slurry with 73% solid content. The positive electrode active slurry is coated on aluminum foil and then rolled and punched to make positive electrode sheet.

[0082] (3) The composite solid electrolyte (Example 1) was dissolved in DMF and then poured into a mold. The solvent was evaporated to obtain a 30 μm composite solid electrolyte film.

[0083] (4) The positive electrode, negative electrode and film obtained above are stacked in the order of negative electrode - solid electrolyte film - positive electrode - solid electrolyte film, and the tabs are welded and packaged with aluminum-plastic film to obtain the lithium-ion battery.

[0084] Application Examples 2-7

[0085] A lithium-ion battery differs from Application Example 1 only in that the composite solid electrolyte particles obtained in Examples 2 to 7 are used to replace the composite solid electrolyte particles obtained in Example 1, while the other materials and preparation processes are the same as in Application Example 1.

[0086] Application Example 8

[0087] A lithium-ion battery, the manufacturing process of which includes:

[0088] (1) Using graphite / silicon-carbon composite material as negative electrode active material, SP as conductive agent and SBR as binder, SBR is dissolved in deionized water to obtain adhesive solution. The above materials are homogenized in a planetary mixer at a mass ratio of 95:2.5:2.5 to obtain negative electrode active slurry with 55% solid content. The negative electrode active slurry is coated on copper foil and then rolled and punched to make negative electrode sheet.

[0089] (2) Using NCM811 material as positive electrode active material, CNT as conductive agent, and PVDF as binder, PVDF is dissolved in NMP to obtain a glue solution. The above materials are homogenized in a planetary mixer at a mass ratio of 97.5:1:1.5 to obtain a positive electrode active slurry with a solid content of 73%. The positive electrode active slurry is coated on aluminum foil and then rolled and punched to make a positive electrode sheet.

[0090] (3) In an argon-filled glove box, LiPF6 was dissolved at a concentration of 1 mol / L in an electrolyte composed of EC, EMC and DMC in a volume ratio of 1:1:1, and 3% FEC was added. After stirring for 3 hours, the composite solid electrolyte (Example 8) was added to the above electrolyte to obtain the composite electrolyte.

[0091] (4) The positive electrode, negative electrode and film obtained above are stacked in the order of negative electrode - separator - positive electrode - separator, and the tabs are welded, aluminum-plastic film is encapsulated, and the composite electrolyte obtained in step (3) is injected to obtain the lithium-ion battery.

[0092] Comparative application examples 1-2

[0093] A lithium-ion battery differs from Application Example 1 only in that the composite solid electrolyte particles obtained in Comparative Examples 1 and 2 are used instead of the composite solid electrolyte particles obtained in Example 1. All other materials and preparation processes are the same as in Application Example 1.

[0094] Comparative Application Example 3

[0095] A lithium-ion battery differs from Application Example 8 only in that the composite solid electrolyte provided in Example 12 is not added in step (3), while the other materials and preparation methods are the same as in Application Example 8.

[0096] Performance testing:

[0097] (1) Morphological observation: The composite solid electrolyte obtained in Example 1 was tested using a cold field emission scanning electron microscope (Hitachi, Regulus 8230, Japan). The scanning electron microscope image of the composite solid electrolyte obtained in Example 1 at a magnification of 5.00k is shown below. Figure 1 As shown, the SEM image of the composite solid electrolyte obtained in Example 1 at a magnified 10.0 kJ is as follows. Figure 2 As shown, according to Figure 1 and Figure 2 It can be seen that the composite solid electrolyte obtained in Example 1 has a small particle size and a dark coating layer structure on the surface, indicating that the organic components are uniformly attached to the particle surface.

[0098] (2) Mechanical properties: Mechanical properties were measured using an instrumental nanoindentation device (G200 nanoindenter, KLA) at a constant strain rate of 0.05 s⁻¹. -1 Below, using formula 1 / E r =(1-v 2 ) / E+(1-v i 2 ) / E i Determine the elastic modulus, where v and v i These are the Poisson's ratios of the sample and the indenter, respectively, where Ei is the elastic modulus of the indenter, and E... r =0.5S√(π / A) c S is the unloading slope of the load-displacement curve after the initial pressure head is removed.

[0099] (3) Ionic conductivity: A stainless steel / electrolyte / stainless steel button cell was assembled in a glove box filled with argon gas. After standing for one day, an electrochemical AC impedance spectroscopy test was performed using a Bio-logic VMP-300 electrochemical workstation. The frequency range was 7kHz to 500mHz and the test temperature was 30 to 80℃.

[0100] Ionic conductivity (σ) is calculated using σ = L / RS, where L is the electrolyte membrane thickness in mm, R is the electrolyte resistance in ohms, and S is the effective electrode surface area in mm². 2 .

[0101] The solid electrolytes obtained in Examples 1-8 and Comparative Examples 1-2 were tested according to the above test methods, and the test results are shown in Table 1:

[0102] Table 1

[0103]

[0104]

[0105] As can be seen from the data in Table 1, the composite electrolyte provided by this invention has a high elastic modulus and a high ionic conductivity. Specifically, the composite solid electrolytes obtained in Examples 1 and 4-8 have an ionic conductivity of 3.5 × 10⁻⁶ GPa, ranging from 118 to 137 GPa. -4 ~4.5×10 -4 S / cm; The composite solid electrolyte obtained in Example 2 has a Pa of 148 GPa and an ionic conductivity of 1.2 × 10⁻⁶. -3 S / cm; The composite solid electrolyte obtained in Example 3 has a 58 GPa ionic conductivity of 2.5 × 10⁻⁶. -4 S / cm; while the polymer solid electrolyte particles and oxide solid electrolyte particles provided in Comparative Examples 1 and 2 not only have lower elastic modulus but also lower ionic conductivity.

[0106] (4) Electrical performance: The test was conducted using a Xinwei battery tester. The lithium-ion battery was installed on the battery tester, with the red terminal connected to the positive terminal and the black terminal connected to the negative terminal. The battery was then set up as follows: ① rest for 12 hours; ② constant current charging, current 0.1C, cutoff voltage 4.2V; ③ constant current discharging, current 0.1C, cutoff voltage 2.7V; ④ 100 cycles; ⑤ end.

[0107] The lithium-ion batteries provided in Test Cases 1-8 and Comparative Application Examples 1-3 were tested according to the above test methods. The test results are shown in Table 2.

[0108] Table 2

[0109] Capacity retention rate / % Application Example 1 95 Application Example 2 96 Application Example 3 94 Application Example 4 93 Application Example 5 94 Application Example 6 94 Application Example 7 94 Application Example 8 97 Comparative Application Example 1 92 Comparative Application Example 2 92 Comparative Application Example 3 91

[0110] As can be seen from Table 2, the lithium-ion battery prepared using the composite solid electrolyte provided by the present invention has excellent cycle performance. Specifically, the lithium-ion batteries provided in Application Examples 1 to 8 have a capacity retention rate of 93 to 96% after 100 cycles, while the lithium-ion batteries provided in Application Examples 1 to 3 have a capacity retention rate of only 91 to 92% after 100 cycles.

[0111] The applicant declares that this invention illustrates a composite solid electrolyte particle, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above process steps, meaning that this invention does not necessarily rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials used in this invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this invention.

Claims

1. A composite solid-state electrolyte particle, characterized by, The core-shell structure of the composite solid electrolyte particle comprises an inorganic solid electrolyte in a core layer; The shell layer of the core-shell structure comprises an organic component, which comprises an organic solid electrolyte and a polymer that does not swell in electrolyte; The particle size of the composite solid electrolyte particle is 30-500 nm; The thickness of the shell layer is not more than 50 nm; The organic solid electrolyte comprises a polyionic liquid type solid electrolyte; The polymer that does not swell in electrolyte comprises any one or a combination of at least two of PP, PE, PVDF or PTFE.

2. The composite solid-state electrolyte particle of claim 1, wherein The inorganic solid electrolyte comprises any one or a combination of at least two of an oxide solid electrolyte, a sulfide solid electrolyte or a chloride solid electrolyte.

3. The composite solid-state electrolyte particle of claim 2, wherein, The oxide solid electrolyte comprises any one or a combination of at least two of a NASICON type oxide solid electrolyte, a garnet type oxide solid electrolyte or a perovskite type oxide solid electrolyte.

4. The composite solid-state electrolyte particle of claim 3, wherein The NASICON type oxide solid electrolyte comprises any one or a combination of at least two of lithium titanium aluminum phosphates, lithium titanium phosphates, lithium germanium aluminum phosphates, lithium zirconium silicon phosphates, lithium germanium phosphates or lithium zirconium phosphates.

5. The composite solid-state electrolyte particle of claim 3, wherein The garnet type oxide solid electrolyte comprises lithium zirconium lanthanum oxide.

6. The composite solid-state electrolyte particle of claim 3, wherein The perovskite type oxide solid electrolyte comprises lithium titanium lanthanum oxide.

7. The composite solid-state electrolyte particle of claim 2, wherein The sulfide solid electrolyte includes any one or a combination of at least two of a Li-P-S type solid electrolyte, a Li 11-n M 2-n P 1+n S 12 type solid electrolyte, or a Li6PS5X type solid electrolyte, Wherein, 0 < n < 1, M is selected from Ge, Sn or Si, and X is selected from Cl, Br or I.

8. The composite solid-state electrolyte particle of claim 7, wherein, The Li-P-S type solid-state electrolyte includes Li3PS4 and / or Li7P3S 11 .

9. The composite solid-state electrolyte particle of claim 7, wherein, The Li 11-n M 2-n P 1+n S 12 Type solid-state electrolyte includes Li2S-GeS2-P2S5.

10. The composite solid-state electrolyte particle of claim 1, wherein, The monomer of the polyionic liquid type solid electrolyte comprises an ionic liquid and / or a grafted ionic liquid.

11. The composite solid-state electrolyte particle of claim 10, wherein, The ionic liquid is composed of an ionic liquid cation and an ionic liquid anion.

12. The composite solid-state electrolyte particle of claim 10, wherein The grafted ionic liquid is composed of an ionic liquid cation, an ionic liquid anion and a grafting monomer.

13. The composite solid-state electrolyte particle of claim 12, wherein, The ionic liquid cation comprises any one of or a combination of at least two of [Emim] + , [Bmin] + , [Cmim] + , [Daim] + , [Veim] + , [BCNim] + , [PP 14 ] + , [Pyr 13 ] + , [N 111 ] + , [DEME] + or [P 111i4 ] + .

14. The composite solid-state electrolyte particle of claim 12, wherein, The ionic liquid anion comprises any one of [BF4] - , [N(CN)2]2 - , [CH3COO] - , [TfO] - , [FSI] - or [TFSI] - or a combination of at least two thereof.

15. The composite solid-state electrolyte particle of claim 12, wherein, The grafting monomer comprises oxirane and / or methyl methacrylate.

16. The composite solid-state electrolyte particle of claim 10, wherein The ionic liquid comprises any one of [Pyr 13 ][FSI], [Emim][TFSI], or [PP 14 ][TFSI], or a combination of at least two thereof.

17. The composite solid-state electrolyte particle of claim 10, wherein, The grafted ionic liquid comprises PMMA-[Pyr 13 Any one or a combination of at least two of PEO-[Emim][TFSI], PEO-[Bmim][TFSI], PEO-[Pyr] or PEO-[FSI].

18. The composite solid-state electrolyte particle of claim 1, wherein, The polyionic liquid type solid electrolyte comprises any one or a combination of at least two of a polyimidazolium type solid electrolyte, a polypyrryl type solid electrolyte, a polypyridyl type solid electrolyte, a polypiperidinium type solid electrolyte or a polyquaternary ammonium salt type solid electrolyte.

19. The composite solid-state electrolyte particle of claim 18, wherein, The polyionic liquid type solid-state electrolyte includes any one of P[Pyr 13 ][FSI], P[Emim][TFSI], P[PP 14 ][TFSI], P{PMMA-[Pyr 13 ][FSI]} or P{PEO-[Emim][TFSI]} or a combination of at least two thereof.

20. A method of producing the composite solid electrolyte particle according to any one of claims 1 to 19, characterized by, The preparation method comprises method A or method B; The method A comprises mixing the core layer and the shell layer in water, and spray drying to obtain the composite solid electrolyte particle; The method B comprises mixing the monomers of the core layer and the shell layer in water, adding a thermal initiator, and spray drying to obtain the composite solid electrolyte particle.

21. The method of claim 20, wherein, In the method A and the method B, the mixing is further followed by a ball milling step.

22. The preparation method according to claim 20, characterized in that, In the method A and the method B, the spray drying is performed at a raw material supply amount of 10-30 L / h, a hot air inlet temperature of 180-300°C and an exhaust air temperature of 80-120°C.

23. The preparation method according to claim 20, characterized in that, In the method B, the thermal initiator comprises any one or a combination of at least two of azobisisobutyronitrile, azobisisoheptyl nitrile, dibenzoyl peroxide, dialkyl peroxide, cumene hydroperoxide or tert-butyl hydroperoxide.

24. Use of the composite solid electrolyte particle according to any one of claims 1-19 in a solid-state battery.

25. The use according to claim 24, characterized in that, The solid-state battery includes a solid-state lithium-ion battery or a solid-state sodium-ion battery. The solid-state battery includes a solid-state lithium-ion battery or a solid-state sodium-ion battery.

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