High-nickel positive electrode material coated with organic-inorganic hybrid solid polymer electrolyte and preparation method and application of high-nickel positive electrode material

Abstract

The invention provides an organic-inorganic hybrid solid-state polymer electrolyte coated high-nickel positive electrode material as well as a preparation method and application thereof, and relates to the technical field of all-solid-state lithium batteries. The high-nickel positive electrode material coated with the organic-inorganic hybrid solid polymer electrolyte comprises an inner core and an organic-inorganic hybrid coating layer coated on the surface of the inner core, the inner core is made of a high-nickel positive electrode material; the organic-inorganic hybrid coating layer comprises a ring-opening copolymer of maleic anhydride and 1, 3-dioxolame, and Li3PO4 nanocrystals are embedded into the ring-opening copolymer of maleic anhydride and 1, 3-dioxolame in situ. According to the invention, a flexible and compact coating layer with ionic conductivity is constructed on the surface of the high-nickel positive electrode material, so that the problems of violent interface side reaction, large interface impedance and poor cycling stability existing between the high-nickel positive electrode material and sulfide solid electrolyte are solved; therefore, the electrochemical performance of the material in a sulfide all-solid-state lithium battery is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of all-solid-state lithium battery technology, and in particular to a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte, its preparation method, and its application. Background Technology

[0002] All-solid-state lithium batteries (ASSBs) are considered ideal for next-generation energy storage devices due to their high energy density and safety. One of their performance bottlenecks lies in the significant interfacial impedance on the cathode side, including poor physical contact between the cathode active material (such as high-nickel ternary materials, lithium-rich manganese-based materials, and lithium cobalt oxide), space charge layer effects, and side reactions. A traditional solution is to mix the cathode active material with a sulfide or oxide solid electrolyte to form a composite cathode. However, sulfide electrolytes have poor chemical stability and readily react with the cathode material; oxide electrolytes have high hardness, high sintering temperature, and poor interfacial compatibility with the cathode material. Therefore, developing a novel cathode composite material structure to achieve superior interfacial ion transport kinetics and chemical stability is crucial for advancing the commercial application of all-solid-state lithium batteries.

[0003] High-nickel layered oxide LiNi x Co y Mn z The combination of O2 (NCM) and the sulfide solid electrolyte Li6PS5Cl (LPSCl) can achieve >300 Wh·kg -1 While both offer the same energy density, the interface between them presents the following problems: LPSCl has a narrow electrochemical window (~1.7–2.1 V vs Li). + Li is oxidized to SO4 at >4 V. 2- PSO x Insulation byproducts, such as those produced, lead to a continuous increase in interfacial impedance; Traditional inorganic coatings, such as the Al2O3-LiNbO3 co-coating scheme represented by CN120149360A, attempt to balance interfacial stability and ion transport by combining rigid Al2O3 (physical barrier) with highly ionicly conductive LiNbO3 (ion channel). However, this strategy has inherent drawbacks: it is still essentially a rigid interface and cannot adapt to volume changes; the "physical mixing" coating has insufficient interfacial bonding and uniformity; and the process is complex and may introduce impurities. Multi-coating schemes, exemplified by CN120864537A, utilize a complex structure of "gradient-doped core + magnesium doped layer + carbon coating layer + Al2O3 outer coating layer" to enhance material performance. This reflects the current situation where a single functional layer cannot meet comprehensive requirements. However, this strategy also has its problems: the structure is too complex, making industrialization extremely difficult and costly; each layer functions independently, lacking synergistic enhancement effects, and failing to resolve the fundamental contradiction with sulfide electrolytes. While a single rigid inorganic coating layer (such as Al2O3) has relatively simple processing, it suffers from poor ionic conductivity and is prone to cracking; introducing a high-ionic-conductivity inorganic phase (such as LiNbO3) for composite formation is difficult to overcome due to its rigid nature and complex processing; and constructing a multi-layer structure makes the process exceptionally complex and drastically increases costs. The fundamental reason is that these solutions are all limited to improvements within the scope of pure inorganic materials, and have failed to introduce flexible components that can adapt to volume changes and achieve close contact, and to hybridize with rigid inorganic phases in situ at the nanoscale, thereby achieving synergistic protection that combines rigidity and flexibility.

[0004] Organic coating solutions, such as the one in CN121149184A that incorporates a copolymer of maleic anhydride and 1,3-dioxolane, suffer from several drawbacks. The organic layer lacks sufficient mechanical strength to accommodate volume changes during high-nickel cathode cycling, leading to cracking and failure over long-term use. Furthermore, its limited interfacial stability fails to completely suppress oxidation side reactions of sulfide electrolytes under high voltage, potentially resulting in interfacial impedance accumulation. Moreover, controlling the coating thickness is challenging; excessive thickness leads to decreased electronic conductivity, increasing battery polarization and capacity decay, while insufficient thickness results in incomplete coating and ineffective isolation between the positive and negative electrodes and the electrolyte. Overall, the cycle durability and high-voltage applicability require improvement.

[0005] Therefore, there is an urgent need in this field for a novel coating strategy that can fundamentally reconcile the contradiction between interfacial physical contact and chemical stability. It should have flexible interfacial adaptability, rigid physical barrier function, and efficient ion transport channels, and its preparation process must be simple, economical, and suitable for large-scale production.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte, its preparation method and application, aiming to solve the technical problems of severe interfacial side reactions, high interfacial impedance and poor cycle stability between high-nickel cathode materials and sulfide solid electrolytes.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte, comprising: a core and an organic-inorganic hybrid coating layer covering the surface of the core; The core is a high-nickel cathode material; the organic-inorganic hybrid coating layer includes a ring-opening copolymer of maleic anhydride and 1,3-dioxolane, and Li3PO4 nanocrystals are in situ embedded in the ring-opening copolymer of maleic anhydride and 1,3-dioxolane.

[0009] Furthermore, the chemical formula of the high-nickel cathode material is LiNi. x Co y Mn z O2; where 0.80≤x≤0.96, 0.05≤y≤0.20, 0.05≤z≤0.20.

[0010] Furthermore, the particle size D50 of the high-nickel cathode material is 3.0~5.0 μm.

[0011] Furthermore, the molar ratio of maleic anhydride to 1,3-dioxolane is 1:(9~15).

[0012] Furthermore, the molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 20,000 to 50,000 g / mol.

[0013] Furthermore, the thickness of the organic-inorganic hybrid coating layer is 20~100 nm.

[0014] Furthermore, the content of the Li3PO4 nanocrystals accounts for 5-20% of the total mass of the organic-inorganic hybrid coating layer.

[0015] Furthermore, the Li3PO4 nanocrystals have a particle size of 5~20 nm.

[0016] In a second aspect, the present invention provides a method for preparing a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte as described in the first aspect, the preparation method comprising: Maleic anhydride and 1,3-dioxolane were mixed to obtain a homogeneous MA / DOL solution; The high-nickel cathode material was dispersed in the homogeneous MA / DOL solution and subjected to in-situ ring-opening copolymerization to obtain SPE-NCM powder. Polyvinylpyrrolidone, phosphate and solvent are mixed to obtain inorganic hybrid precursor sol; The SPE-NCM powder was placed in the inorganic hybrid precursor sol, and after composite hybridization, the solvent was removed to obtain a slurry. The slurry is sintered to obtain the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte.

[0017] Furthermore, the molar ratio of maleic anhydride to 1,3-dioxolane is 1:(9~15).

[0018] Furthermore, the concentration of the homogeneous MA / DOL solution is 0.8~1.2 M.

[0019] Furthermore, the preparation of the homogeneous MA / DOL solution was carried out under an inert atmosphere.

[0020] Furthermore, the mass-to-volume ratio of the high-nickel cathode material to the homogeneous MA / DOL solution is 1.0 g:(5~15) mL.

[0021] Furthermore, the dispersion is ultrasonic dispersion; wherein the ultrasonic dispersion power is 100~300 W, and the ultrasonic dispersion time is 10~60 min.

[0022] Furthermore, the in-situ ring-opening copolymerization reaction is carried out under stirring conditions; the temperature of the in-situ ring-opening copolymerization reaction is 20~30℃, and the time of the in-situ ring-opening copolymerization reaction is 3~12 h.

[0023] Furthermore, the dispersion and the in-situ ring-opening copolymerization reaction are carried out under an inert atmosphere.

[0024] Furthermore, the following post-processing steps are included after the in-situ ring-opening copolymerization reaction is completed: The mixture after the in-situ ring-opening copolymerization reaction was centrifuged to collect the solid product; the solid product was washed; and the washed product was dried to obtain the SPE-NCM powder.

[0025] Furthermore, the centrifugal separation speed is 6000~10000 rpm.

[0026] Furthermore, the washing agent used is 1,2-dimethoxyethane.

[0027] Furthermore, the drying is carried out under vacuum conditions, the drying temperature is 60~100℃, and the drying time is 2~10 h.

[0028] Furthermore, the inorganic hybrid precursor sol comprises, by mass percentage: 0.1-1% polyvinylpyrrolidone, 1-3% phosphate, and the remainder is solvent.

[0029] Furthermore, the phosphate is diammonium hydrogen phosphate.

[0030] Furthermore, the solvent is ethanol.

[0031] Furthermore, the mixing of the inorganic hybrid precursor sol is carried out under stirring conditions; the mixing temperature is 20~30℃, and the mixing time is 12~36 h.

[0032] Furthermore, the composite hybridization is carried out under stirring conditions; the temperature of the composite hybridization is 20~30℃, and the time of the composite hybridization is 12~36 h.

[0033] Furthermore, the solvent removal is performed by water bath evaporation; the temperature of the water bath evaporation is 40~60℃.

[0034] Furthermore, the heating rate of the sintering treatment is 2~5℃ / min, the sintering temperature is 300~500℃, and the sintering time is 2~8 h.

[0035] Furthermore, the sintering process is carried out under vacuum and / or an inert atmosphere.

[0036] Thirdly, the present invention provides the application of a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte as described in the first aspect in the preparation of cathode sheets and / or sulfide all-solid-state lithium batteries.

[0037] Fourthly, the present invention provides a positive electrode sheet comprising a high-nickel positive electrode material coated with an organic-inorganic hybrid solid polymer electrolyte as described in the first aspect.

[0038] Furthermore, the positive electrode also includes: a sulfide solid electrolyte, a binder, and conductive carbon.

[0039] Fifthly, the present invention provides a sulfide all-solid-state lithium battery, the sulfide all-solid-state lithium battery comprising the positive electrode sheet as described in the fourth aspect.

[0040] Compared with the prior art, the present invention has the following beneficial effects: (1) The high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte of the present invention forms an H-SPE-NCM cathode material with both flexibility and rigidity. It is constructed by maleic anhydride and 1,3-dioxolane ring-opening copolymer to form a flexible and ion-conducting organic matrix. Its polar functional groups can anchor the residual lithium salt on the high-nickel surface and passivate the active sites. The in-situ embedded Li3PO4 nanocrystals not only provide a high ion conductivity path, but also form Lewis acid-base interactions with the polymer chain to enhance the interfacial Li +Migration number and thermal stability; the two work together to construct a coating layer that combines chemical bonding, gradient modulus and adaptive deformation capability, effectively suppressing interfacial side reactions, mitigating microcrack propagation and reducing transition metal dissolution during charge and discharge, significantly improving the cycle retention rate, rate performance and high-temperature safety of high-nickel cathode.

[0041] (2) The present invention mixes the H-SPE-NCM cathode material with sulfide solid electrolyte Li6PS5Cl (LPSCl), binder and conductive carbon to prepare cathode sheet, and assembles sulfide-based solid battery. This solves the problems of LPSCl being oxidized under high pressure, which leads to continuous increase in interfacial impedance, and the high rigidity, complex process, easy crack penetration, and narrow electrochemical stability window of traditional inorganic coatings, which will trigger electrochemical reduction reaction during battery cycling, resulting in undesirable interfacial reduction byproducts, high electronic conductivity, grain boundary resistance, as well as voids and cracks. Ultimately, the overall performance of the battery is improved. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the process flow for preparing the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte provided by the present invention. Detailed Implementation

[0044] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0045] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In a first aspect, the present invention provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte, comprising: a core and an organic-inorganic hybrid coating layer covering the surface of the core; The core is a high-nickel cathode material; the organic-inorganic hybrid coating layer includes a ring-opening copolymer of maleic anhydride (MA) and 1,3-dioxolane (DOL), and Li3PO4 nanocrystals are in situ embedded in the ring-opening copolymer of maleic anhydride and 1,3-dioxolane.

[0047] It should be noted that the cathode material of this invention includes a high-nickel cathode material matrix and an organic-inorganic hybrid coating layer covering its surface; wherein, the hybrid coating layer is composed of a solid polymer electrolyte network formed by in-situ ring-opening copolymerization of maleic anhydride (MA) and 1,3-dioxolane (DOL), and Li3PO4 nanocrystals generated in situ and embedded therein; the coating layer is dense, continuous, and ionicly conductive. This structure can overcome problems such as poor physical contact between the high-nickel cathode material and the solid electrolyte, space charge layer effect, and side reactions, by introducing Li3PO4 nanocrystals into the solid-polymer-electrolyte coating layer to construct an "organic-inorganic hybrid protective layer," while retaining the in-situ polymerization, flexibility, and Li3PO4 nanocrystals. + Conductivity is enhanced to further improve mechanical strength, thermal stability, and interface durability. Simultaneously, a flexible, dense, and ionicly conductive organic-inorganic hybrid solid-state polymer electrolyte coating layer is constructed on the surface of the high-nickel cathode material, thereby significantly improving its electrochemical performance in sulfide all-solid-state lithium batteries.

[0048] As an optional implementation, the high-nickel cathode material has the chemical formula LiNi. x Co y Mn z O2; where 0.80≤x≤0.96, 0.05≤y≤0.20, 0.05≤x≤0.20.

[0049] As an optional implementation, LiNi x Co y Mn z In O2, x is between 0.80 and 0.96, for example, it can be 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, etc.

[0050] As an optional implementation, LiNi x Co y Mn zIn O2, y is 0.05~0.20, for example, it can be 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, etc.

[0051] As an optional implementation, LiNi x Co y Mn z In O2, z is 0.05~0.20, for example, it can be 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, etc.

[0052] As a preferred embodiment, the high-nickel cathode material is single-crystal LiNi. 0.8 Co 0.1 Mn 0.1 O2 (NCM811) cathode material.

[0053] As an optional implementation, the particle size D50 of the high-nickel cathode material is 3.0~5.0 μm, for example, it can be 3.0 μm, 3.2 μm, 3.4 μm, 3.6 μm, 3.8 μm, 4.0 μm, 4.2 μm, 4.4 μm, 4.6 μm, 4.8 μm, 5.0 μm, etc.

[0054] As an optional implementation, the molar ratio of maleic anhydride to 1,3-dioxolane is 1:(9~15), for example, it can be 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, etc.

[0055] In a preferred embodiment, the molar ratio of maleic anhydride to 1,3-dioxolane is 1:10.

[0056] As an optional embodiment, the molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 20,000 to 50,000 g / mol, for example, it can be 20,000 g / mol, 25,000 g / mol, 30,000 g / mol, 35,000 g / mol, 40,000 g / mol, 45,000 g / mol, 50,000 g / mol, etc.

[0057] As an optional implementation, the thickness of the organic-inorganic hybrid coating layer is 20~100 nm, for example, it can be 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, etc.

[0058] In a preferred embodiment, the thickness of the organic-inorganic hybrid coating layer is 30 nm.

[0059] As an optional implementation, the content of the Li3PO4 nanocrystals accounts for 5 to 20% of the total mass of the organic-inorganic hybrid coating layer, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.

[0060] As an optional implementation, the Li3PO4 nanocrystals have a particle size of 5~20 nm, for example, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc.

[0061] In a second aspect, the present invention provides a method for preparing a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte as described in the first aspect, the preparation method comprising: Maleic anhydride and 1,3-dioxolane were mixed to obtain a homogeneous MA / DOL solution; The high-nickel cathode material was dispersed in the homogeneous MA / DOL solution and subjected to in-situ ring-opening copolymerization to obtain SPE-NCM powder. Polyvinylpyrrolidone, phosphate and solvent are mixed to obtain inorganic hybrid precursor sol; The SPE-NCM powder was placed in the inorganic hybrid precursor sol, and after composite hybridization, the solvent was removed to obtain a slurry. The slurry is sintered to obtain the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte.

[0062] It should be noted that the preparation method described in this invention exhibits multiple significant beneficial effects through multi-step precise control and synergistic effects, comprehensively optimizing the performance of high-nickel cathode materials: First, the preparation process employs an in-situ ring-opening copolymerization reaction, allowing maleic anhydride and 1,3-dioxolane to directly form a solid polymer electrolyte coating (SPE) on the surface of the high-nickel cathode material. This ensures that the coating layer is tightly bonded to the substrate and provides uniform coverage, effectively avoiding problems such as interface peeling and incomplete coating that are common in traditional coating processes. This lays a stable foundation for subsequent hybridization modification. At the same time, this in-situ generation method does not require harsh conditions such as high temperature and high pressure. The process is mild and easy to control, reducing the difficulty and cost of industrial production. It also reduces the risk of introducing additional impurities and ensures the purity of the material.

[0063] Secondly, the organic-inorganic hybrid system achieves a synergistic effect of "rigidity and flexibility." The organic polymer matrix endows the coating layer with good flexibility and deformation capability, which can adapt to the volume changes of the high-nickel cathode material during charge-discharge cycles, alleviate interfacial stress concentration, inhibit the disintegration of the material surface structure, and maintain the stability of the solid-solid contact interface. Meanwhile, the inorganic nanocrystals Li3PO4 generated from phosphate decomposition, after being embedded in the organic network, significantly improve the mechanical strength and thermal stability of the coating layer, forming an effective physical barrier that hinders interfacial side reactions between the high-nickel cathode and the sulfide solid electrolyte, reduces the formation of insulating byproducts, and lowers the accumulation of interfacial impedance. Furthermore, the synergistic effect of the inorganic nanocrystals and organic polymers also optimizes the lithium-ion transport channels, improves ion transport efficiency, and alleviates battery polarization.

[0064] Furthermore, the microporous channels generated by the decomposition of polyvinylpyrrolidone during sintering further optimize the microstructure of the coating layer, ensuring smooth lithium-ion transport and providing a buffer space for material volume changes, thus further enhancing interfacial stability. The entire preparation process is coherent and logically sound, with each step forming a synergistic effect. The resulting organic-inorganic hybrid coated high-nickel cathode material exhibits significant improvements in key performance aspects such as cycle stability, interfacial compatibility, and ionic conductivity. It effectively overcomes the inherent defects of traditional single organic or inorganic coating layers, providing reliable material support for performance breakthroughs in sulfide-based all-solid-state lithium batteries and significantly improving the energy density, long cycle life, and safety of all-solid-state lithium batteries.

[0065] As an optional implementation, the molar ratio of maleic anhydride to 1,3-dioxolane is 1:(9~15), for example, it can be 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, etc.

[0066] As an optional implementation, the concentration of the homogeneous MA / DOL solution is 0.8~1.2 M, for example, it can be 0.8 M, 0.85 M, 0.9 M, 0.95 M, 1 M, 1.05 M, 1.1 M, 1.15 M, 1.2 M, etc.

[0067] In a preferred embodiment, the concentration of the homogeneous MA / DOL solution is 1 M.

[0068] As an optional implementation, the preparation of the homogeneous MA / DOL solution is carried out under an inert atmosphere.

[0069] As an optional implementation, the inert atmosphere includes any one or a combination of at least two of nitrogen, helium, and argon.

[0070] As an optional implementation, the mass-to-volume ratio of the high-nickel cathode material to the homogeneous MA / DOL solution is 1.0 g:(5~15) mL, for example, it can be 1.0 g:5 mL, 1.0 g:6 mL, 1.0 g:7 mL, 1.0 g:8 mL, 1.0 g:9 mL, 1.0 g:10 mL, 1.0 g:11 mL, 1.0 g:12 mL, 1.0 g:13 mL, 1.0 g:14 mL, 1.0 g:15 mL, etc.

[0071] As an optional implementation, the dispersion is ultrasonic dispersion (to disperse particles and activate surface alkaline sites); wherein the power of the ultrasonic dispersion is 100~300 W, for example, 100 W, 120 W, 140 W, 160 W, 180 W, 200 W, 220 W, 240 W, 260 W, 280 W, 300 W, etc., and the ultrasonic dispersion time is 10~60 min, for example, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc.

[0072] In a preferred embodiment, the dispersion is ultrasonic dispersion (to disperse particles and activate surface alkaline sites); wherein the ultrasonic dispersion power is 100 W and the ultrasonic dispersion time is 30 min.

[0073] As an optional implementation, the in-situ ring-opening copolymerization reaction is carried out under stirring conditions (causing MA and DOL to undergo ring-opening copolymerization on the NCM surface, with an SPE protective layer); the temperature of the in-situ ring-opening copolymerization reaction is 20~30℃, for example, 20℃, 22℃, 24℃, 25℃, 26℃, 28℃, 30℃, etc., and the time of the in-situ ring-opening copolymerization reaction is 3~12 h, for example, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, etc.

[0074] In a preferred embodiment, the in-situ ring-opening copolymerization reaction is carried out under stirring conditions (to cause MA and DOL to undergo ring-opening copolymerization on the NCM surface, with an SPE protective layer); the temperature of the in-situ ring-opening copolymerization reaction is 25°C, and the time of the in-situ ring-opening copolymerization reaction is 5 h.

[0075] As an optional implementation, the dispersion and the in-situ ring-opening copolymerization reaction are carried out under an inert atmosphere.

[0076] As an optional implementation, the inert atmosphere includes any one or a combination of at least two of nitrogen, helium, and argon.

[0077] As an optional implementation, the following post-processing steps are further included after the in-situ ring-opening copolymerization reaction is completed: The mixture after the in-situ ring-opening copolymerization reaction was centrifuged to collect the solid product; the solid product was washed; and the washed product was dried to obtain the SPE-NCM powder.

[0078] As an optional implementation, the centrifugal separation speed is 6000~10000 rpm, for example, it can be 6000 rpm, 6500 rpm, 7000 rpm, 7500 rpm, 8000 rpm, 8500 rpm, 9000 rpm, 9500 rpm, 10000 rpm, etc.

[0079] In a preferred embodiment, the centrifugal separation speed is 8000 rpm.

[0080] As an optional implementation, the washing reagent used is 1,2-dimethoxyethane.

[0081] As an optional implementation, the drying is carried out under vacuum conditions, the drying temperature is 60~100℃, for example, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc., and the drying time is 2~10 h, for example, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, etc.

[0082] In a preferred embodiment, the drying is carried out under vacuum conditions, the drying temperature is 80°C, and the drying time is 5 hours.

[0083] As an optional implementation, the inorganic hybrid precursor sol comprises, by mass percentage: 0.1-1% polyvinylpyrrolidone (e.g., 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc.), 1-3% phosphate (e.g., 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, etc.), with the balance being solvent.

[0084] In a preferred embodiment, the inorganic hybrid precursor sol comprises, by mass percentage: 0.1% polyvinylpyrrolidone, 2% phosphate, and the remainder being solvent.

[0085] As an optional implementation, the phosphate is diammonium hydrogen phosphate.

[0086] As an optional implementation, the solvent is ethanol.

[0087] As an optional implementation, the mixing of the inorganic hybrid precursor sol is carried out under stirring conditions; the mixing temperature is 20~30℃, for example, 20℃, 22℃, 24℃, 25℃, 26℃, 28℃, 30℃, etc., and the mixing time is 12~36 h, for example, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, 26 h, 28 h, 30 h, 32 h, 34 h, 36 h, etc.

[0088] In a preferred embodiment, the mixing of the inorganic hybrid precursor sol is carried out under stirring conditions; the mixing temperature is 25°C and the mixing time is 24 h.

[0089] As an optional implementation, the composite hybridization is carried out under stirring conditions; the temperature of the composite hybridization is 20~30℃, for example, it can be 20℃, 22℃, 24℃, 25℃, 26℃, 28℃, 30℃, etc.; the time of the composite hybridization is 12~36 h, for example, it can be 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, 26 h, 28 h, 30 h, 32 h, 34 h, 36 h, etc.

[0090] In a preferred embodiment, the composite hybridization is carried out under stirring conditions; the temperature of the composite hybridization is 25°C, and the time of the composite hybridization is 24 h.

[0091] As an optional implementation, the solvent removal is carried out by water bath evaporation; the temperature of the water bath evaporation is 40~60℃, for example, it can be 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, etc.

[0092] In a preferred embodiment, the solvent removal is performed by water bath evaporation; the temperature of the water bath evaporation is 50°C.

[0093] As an optional implementation, the sintering process is carried out in a tube furnace.

[0094] As an optional implementation, the heating rate of the sintering treatment is 2~5℃ / min, for example, it can be 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min, 5℃ / min, etc.; the sintering temperature is 300~500℃, for example, it can be 300℃, 320℃, 340℃, 360℃, 380℃, 400℃, 420℃, 440℃, 460℃, 480℃, 500℃, etc.; and the sintering time is 2~8 h, for example, it can be 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h, etc.

[0095] In a preferred embodiment, the sintering temperature is 450°C and the sintering time is 5 h.

[0096] As an optional implementation, the sintering process is carried out under a vacuum and / or an inert atmosphere.

[0097] As an optional implementation, the inert atmosphere includes any one or a combination of at least two of nitrogen, helium, and argon.

[0098] As an optional implementation, the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte is prepared by the following steps (the overall coating process is attached). Figure 1 (as shown) S1. Preparation of polymerization solution: Under an inert atmosphere, maleic anhydride was dissolved in anhydrous 1,3-dioxolane and magnetically stirred until completely dissolved to obtain a homogeneous MA / DOL solution.

[0099] S2, in-situ open-ring copolymer coating: Single-crystal LiNi was added to the homogeneous MA / DOL solution obtained in step S1. x Co y Mn zO2 high-nickel cathode material; under inert atmosphere protection, it is first subjected to ultrasonic treatment to fully disperse the high-nickel cathode material particles and activate the alkaline groups on its surface; then, it is stirred to allow maleic anhydride and 1,3-dioxolane to undergo an in-situ ring-opening copolymerization reaction initiated by the alkaline sites on the cathode material surface, thereby forming a preliminary solid polymer electrolyte coating layer on the material surface.

[0100] S3. Washing and drying: The mixture after the reaction in step S2 is centrifuged to collect the solid product; the solid product is washed to remove unreacted monomers and free polymers that are not attached to the material surface; the washed product is vacuum dried to obtain SPE-NCM powder with a surface pre-coated with solid polymer electrolyte.

[0101] S4. Preparation of inorganic hybrid precursor sol: Polyvinylpyrrolidone and phosphate were dissolved in a solvent and stirred to form a homogeneous sol, thus obtaining an inorganic hybrid precursor sol.

[0102] S5, Composite Hybridization and Solvent Evaporation: The SPE-NCM powder obtained in step S3 is added to the inorganic hybrid precursor sol prepared in step S4, and stirring is continued to make the precursor sol uniformly adsorbed on the surface of the SPE-NCM powder. Then, the entire system is placed in a water bath and the solvent is slowly evaporated to remove it until a viscous slurry is formed.

[0103] S6. Vacuum sintering treatment: The viscous slurry obtained in step S5 is transferred to a vacuum tube furnace and sintered under vacuum or inert atmosphere. During this process, polyvinylpyrrolidone decomposes and generates microporous channels, while phosphate decomposes to generate Li3PO4 nanocrystals. The Li3PO4 nanocrystals are embedded in situ and firmly bonded to the solid polymer electrolyte network formed in step S2, ultimately forming the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte, denoted as H-SPE-NCM.

[0104] Thirdly, the present invention provides the application of a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte as described in the first aspect in the preparation of cathode sheets and / or sulfide all-solid-state lithium batteries.

[0105] Fourthly, the present invention provides a positive electrode sheet comprising a high-nickel positive electrode material coated with an organic-inorganic hybrid solid polymer electrolyte as described in the first aspect.

[0106] As an optional implementation, the positive electrode further includes: a sulfide solid electrolyte, a binder, and conductive carbon.

[0107] As an optional implementation, the sulfide solid electrolyte includes Li6PS5Cl.

[0108] As an optional implementation, the adhesive includes styrene-butadiene rubber (SEBs).

[0109] As an optional implementation, the conductive carbon includes vapor-grown carbon fiber (VGCF).

[0110] As an optional implementation, the mass ratio of the high-nickel cathode material, sulfide solid electrolyte, binder and conductive carbon coated by the organic-inorganic hybrid solid polymer electrolyte is (70~80):(15~25):(1~3):(1~3); Among them, the positive electrode material "70~80" can be, for example, 70, 72, 74, 76, 78, 80, etc.; Among them, the adhesive "15~25" can be, for example, 15, 17, 19, 20, 21, 23, 25, etc.; Among them, the adhesive "1~3" can be, for example, 1, 1.5, 2, 2.5, 3, etc.; Among them, the conductive carbon "1~3" can be, for example, 1, 1.5, 2, 2.5, 3, etc.

[0111] In a preferred embodiment, the mass ratio of the sulfide solid electrolyte, binder, and conductive carbon is 75:20:3:2.

[0112] Fifthly, the present invention provides a sulfide all-solid-state lithium battery, the sulfide all-solid-state lithium battery comprising the positive electrode sheet as described in the fourth aspect.

[0113] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0114] Example 1 This embodiment provides a high-nickel cathode material (H-SPE-NCM811 cathode material) coated with an organic-inorganic hybrid solid polymer electrolyte. The H-SPE-NCM811 cathode material is prepared by the following steps: S1. Preparation of polymerization solution: In an argon-filled glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), take a dry 250 mL three-necked flask and add 100 mL of anhydrous 1,3-dioxolane (DOL, moisture ≤ 50 ppm); then, weigh 9.8 g (0.1 mol) maleic anhydride (MA, ≥ 99%) and add it to the flask; seal the three-necked flask and remove it from the glove box, place it on a magnetic stirrer, and stir at 500 rpm for 2 h at 25 °C until the maleic anhydride is completely dissolved, resulting in a clear and transparent homogeneous MA / DOL solution with a concentration of 1 M.

[0115] S2, in-situ open-ring copolymer coating: Reconnect the three-necked flask to the argon protection system; add 10.0 g of single-crystal LiNi to the solution. 0.8 Co 0.1 Mn 0.1 O2 (NCM811, D50=5 μm) positive electrode material; then, the system was placed in an ultrasonic cell disruptor and ultrasonically treated for 30 min at 100 W under an argon atmosphere to fully disperse the NCM811 particles and activate their surface alkaline sites; after that, the ultrasonic treatment was removed and the reaction was continued at 25 °C with magnetic stirring (300 rpm) for 5 h to allow MA and DOL to fully undergo ring-opening copolymerization on the NCM811 surface to form a preliminary coating layer of solid polymer electrolyte.

[0116] S3. Washing and drying: After the reaction was complete, the mixture was transferred to a centrifuge tube and centrifuged at 8000 rpm for 10 min to collect the solid product. The solid product was then redispersed and washed with 50 mL of anhydrous 1,2-dimethoxyethane (DME, moisture ≤50 ppm). This process was repeated three times to thoroughly remove unreacted monomers and free polymers. The washed solid product was placed in a vacuum drying oven and dried at 80 °C for 5 h to obtain SPE-NCM811 powder pre-coated with SPE.

[0117] S4. Preparation of inorganic hybrid precursor sol: Weigh 0.1 g of polyvinylpyrrolidone (PVP) and 2.0 g of diammonium hydrogen phosphate ((NH4)2HPO4, ≥99%), dissolve them in 100 mL of anhydrous ethanol, and magnetically stir at 400 rpm for 24 h at 25 °C to form a uniform and transparent sol.

[0118] S5, Composite Hybridization and Solvent Evaporation: Add all of the SPE-NCM811 powder (approximately 10.0 g) obtained in step S3 to the above sol and continue magnetic stirring for 24 h to ensure uniform adsorption of the precursor; then place the entire system in an oil bath at 50°C and slowly evaporate the solvent ethanol until a non-flowing viscous slurry is formed.

[0119] S6. Vacuum sintering treatment: The viscous slurry was transferred to an alumina boat and then placed in a vacuum tube furnace. After the furnace was closed, a vacuum was drawn to -0.1 MPa using a mechanical pump, and then heated from room temperature to 450°C at a heating rate of 3°C / min. The furnace was then held at 450°C for sintering for 5 hours. Subsequently, the furnace was allowed to cool naturally to room temperature, and the product was removed to obtain the final H-SPE-NCM811 cathode material coated with an organic-inorganic hybrid solid polymer electrolyte.

[0120] Example 1: The final organic-inorganic hybrid solid polymer electrolyte-coated H-SPE-NCM811 cathode material core is a high-nickel cathode material NCM811. The organic-inorganic hybrid coating layer comprises a ring-opening copolymer of maleic anhydride and 1,3-dioxolane, with Li3PO4 nanocrystals in situ embedded in the ring-opening copolymer. The high-nickel cathode material NCM811 has a particle size D50 of 5 μm. The thickness of the organic-inorganic hybrid coating layer is 30 nm. The molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 30,000 g / mol. The content of the Li3PO4 nanocrystals accounts for 15% of the total mass of the organic-inorganic hybrid coating layer, and the particle size of the Li3PO4 nanocrystals is 10 nm.

[0121] Example 2 This embodiment provides a high-nickel cathode material (H-SPE-NCM811 cathode material) coated with an organic-inorganic hybrid solid polymer electrolyte. The H-SPE-NCM811 cathode material is prepared by the following steps: S1. Preparation of polymerization solution: In an argon-filled glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), take a dry 250 mL three-necked flask and add 100 mL of anhydrous 1,3-dioxolane (DOL, moisture ≤ 50 ppm). Then weigh 8.0 g (0.08 mol) of maleic anhydride (MA, ≥ 99%) and add it to the flask. Seal the three-necked flask, remove it from the glove box, and place it on a magnetic stirrer. Stir at 500 rpm for 2 h at 25 °C until the maleic anhydride is completely dissolved, yielding a clear and transparent homogeneous MA / DOL solution with a concentration of 0.8 M.

[0122] S2, in-situ open-ring copolymer coating: Reconnect the three-necked flask to the argon protection system. Add 10.0 g of single-crystal LiNi to the solution. 0.8 Co 0.1 Mn 0.1 O2 (NCM811, D50=5μm) positive electrode material; then, the system was placed in an ultrasonic cell disruptor and ultrasonically treated for 30 min at 100 W under an argon atmosphere to fully disperse the NCM811 particles and activate their surface alkaline sites; after that, the ultrasonic treatment was removed and the reaction was continued at 25°C with magnetic stirring (300 rpm) for 5 h to allow MA and DOL to fully undergo ring-opening copolymerization on the NCM811 surface to form a preliminary coating layer of solid polymer electrolyte.

[0123] S3. Washing and drying: After the reaction was completed, the mixture was transferred to a centrifuge tube and centrifuged at 8000 rpm for 10 min to collect the solid product. The solid product was redispersed and washed with 50 mL of anhydrous 1,2-dimethoxyethane (DME, moisture ≤50 ppm). This process was repeated three times to completely remove unreacted monomers and free polymers. The washed solid product was placed in a vacuum drying oven and dried at 80 °C for 5 h to obtain SPE-NCM811 powder with SPE pre-coated surface.

[0124] S4. Preparation of inorganic hybrid precursor sol: Weigh 0.1 g of polyvinylpyrrolidone (PVP) and 2.0 g of diammonium hydrogen phosphate ((NH4)2HPO4, ≥99%), dissolve them in 100 mL of anhydrous ethanol, and magnetically stir at 400 rpm for 24 h at 25 °C to form a uniform and transparent sol.

[0125] S5, Composite Hybridization and Solvent Evaporation: Add all of the SPE-NCM811 powder (approximately 10.0 g) obtained in step 3 to the above sol and continue magnetic stirring for 24 h to ensure uniform adsorption of the precursor; then place the entire system in an oil bath at 50°C and slowly evaporate the solvent ethanol until a non-flowing viscous slurry is formed.

[0126] S6. Vacuum sintering treatment: The viscous slurry was transferred to an alumina boat and then placed in a vacuum tube furnace. After the furnace was closed, a vacuum of -0.1 MPa was applied using a mechanical pump. The furnace was then heated from room temperature to 450°C at a heating rate of 3°C / min and sintered at 450°C for 5 hours. After cooling to room temperature, the final H-SPE-NCM811 cathode material coated with an organic-inorganic hybrid solid polymer electrolyte was obtained.

[0127] Example 2: The final organic-inorganic hybrid solid polymer electrolyte-coated H-SPE-NCM811 cathode material core is a high-nickel cathode material NCM811. The organic-inorganic hybrid coating layer comprises a ring-opening copolymer of maleic anhydride and 1,3-dioxolane, with Li3PO4 nanocrystals in situ embedded in the ring-opening copolymer. The high-nickel cathode material NCM811 has a particle size D50 of 5 μm. The thickness of the organic-inorganic hybrid coating layer is 20 nm. The molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 20,000 g / mol. The content of the Li3PO4 nanocrystals accounts for 20% of the total mass of the organic-inorganic hybrid coating layer, and the particle size of the Li3PO4 nanocrystals is 10 nm.

[0128] Example 3 This embodiment provides a high-nickel cathode material (H-SPE-NCM811 cathode material) coated with an organic-inorganic hybrid solid polymer electrolyte. The H-SPE-NCM811 cathode material is prepared by the following steps: S1. Preparation of polymerization solution: In an argon-filled glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), take a dry 250 mL three-necked flask and add 100 mL of anhydrous 1,3-dioxolane (DOL, moisture ≤ 50 ppm); then weigh 12.0 g (0.12 mol) of maleic anhydride (MA, ≥ 99%) and add it to the flask; seal the three-necked flask and remove it from the glove box, place it on a magnetic stirrer, and stir at 500 rpm for 2 h at 25 °C until the maleic anhydride is completely dissolved, yielding a clear and transparent homogeneous MA / DOL solution with a concentration of 1.2 M.

[0129] S2, in-situ open-ring copolymer coating: Reconnect the three-necked flask to the argon protection system. Add 10.0 g of single-crystal LiNi to the solution. 0.8 Co 0.1 Mn 0.1 O2 (NCM811, D50=5μm) positive electrode material; then, the system was placed in an ultrasonic cell disruptor and ultrasonically treated for 30 min at 100 W under an argon atmosphere to fully disperse the NCM811 particles and activate their surface alkaline sites; after that, the ultrasonic treatment was removed and the reaction was continued at 25°C with magnetic stirring (300 rpm) for 5 h to allow MA and DOL to fully undergo ring-opening copolymerization on the NCM811 surface to form a preliminary coating layer of solid polymer electrolyte.

[0130] S3. Washing and drying: After the reaction was completed, the mixture was transferred to a centrifuge tube and centrifuged at 8000 rpm for 10 min to collect the solid product. The solid product was redispersed and washed with 50 mL of anhydrous 1,2-dimethoxyethane (DME, moisture ≤50 ppm). This process was repeated three times to completely remove unreacted monomers and free polymers. The washed solid product was placed in a vacuum drying oven and dried at 80 °C for 5 h to obtain SPE-NCM811 powder with SPE pre-coated surface.

[0131] S4. Preparation of inorganic hybrid precursor sol: Weigh 0.1 g of polyvinylpyrrolidone (PVP) and 2.0 g of diammonium hydrogen phosphate ((NH4)2HPO4, ≥99%), dissolve them in 100 mL of anhydrous ethanol, and magnetically stir at 400 rpm for 24 h at 25 °C to form a uniform and transparent sol.

[0132] S5, Composite Hybridization and Solvent Evaporation: Add all of the SPE-NCM811 powder (approximately 10.0 g) obtained in step S3 to the above sol and continue magnetic stirring for 24 h to ensure uniform adsorption of the precursor; then place the entire system in an oil bath at 50°C and slowly evaporate the solvent ethanol until a non-flowing viscous slurry is formed.

[0133] S6. Vacuum sintering treatment: The viscous slurry was transferred to an alumina boat and then placed in a vacuum tube furnace. After the furnace was closed, a vacuum was drawn to -0.1 MPa using a mechanical pump. The furnace was then heated from room temperature to 450°C at a heating rate of 3°C / min and sintered at 450°C for 5 hours. After cooling to room temperature, the final H-SPE-NCM811 cathode material coated with an organic-inorganic hybrid solid polymer electrolyte was obtained.

[0134] Example 3: The final organic-inorganic hybrid solid polymer electrolyte-coated H-SPE-NCM811 cathode material core is a high-nickel cathode material NCM811; the organic-inorganic hybrid coating layer includes a ring-opening copolymer of maleic anhydride and 1,3-dioxolane, and Li3PO4 nanocrystals are in situ embedded in the ring-opening copolymer of maleic anhydride and 1,3-dioxolane; wherein, the particle size D50 of the high-nickel cathode material NCM811 is 5 μm; the thickness of the organic-inorganic hybrid coating layer is 50 nm; the molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 50,000 g / mol; the content of the Li3PO4 nanocrystals accounts for 5% of the total mass of the organic-inorganic hybrid coating layer, and the particle size of the Li3PO4 nanocrystals is 10 nm.

[0135] Example 4: This embodiment provides a high-nickel cathode material (H-SPE-NCM811 cathode material) coated with an organic-inorganic hybrid solid polymer electrolyte. The H-SPE-NCM811 cathode material is prepared by the following steps: S1. Preparation of polymerization solution: In an argon-filled glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), take a dry 250 mL three-necked flask and add 100 mL of anhydrous 1,3-dioxolane (DOL, moisture ≤ 50 ppm); then, weigh 9.8 g (0.1 mol) maleic anhydride (MA, ≥ 99%) and add it to the flask; seal the three-necked flask and remove it from the glove box, place it on a magnetic stirrer, and stir at 500 rpm for 2 h at 25 °C until the maleic anhydride is completely dissolved, resulting in a clear and transparent homogeneous MA / DOL solution with a concentration of 1 M.

[0136] S2, in-situ open-ring copolymer coating: Reconnect the three-necked flask to the argon protection system. Add 10.0 g of single-crystal LiNi to the solution. 0.8 Co 0.1 Mn 0.1 O2 (NCM811, D50=5μm) positive electrode material; then, the system was placed in an ultrasonic cell disruptor and ultrasonically treated for 30 min at 100 W under an argon atmosphere to fully disperse the NCM811 particles and activate their surface alkaline sites; after that, the ultrasonic treatment was removed and the reaction was continued at 25°C with magnetic stirring (300 rpm) for 5 h to allow MA and DOL to fully undergo ring-opening copolymerization on the NCM811 surface to form a preliminary coating layer of solid polymer electrolyte.

[0137] S3. Washing and drying: After the reaction was completed, the mixture was transferred to a centrifuge tube and centrifuged at 8000 rpm for 10 min to collect the solid product. The solid product was redispersed and washed with 50 mL of anhydrous 1,2-dimethoxyethane (DME, moisture ≤50 ppm). This process was repeated three times to completely remove unreacted monomers and free polymers. The washed solid product was placed in a vacuum drying oven and dried at 80 °C for 5 h to obtain SPE-NCM811 powder with SPE pre-coated surface.

[0138] S4. Preparation of inorganic hybrid precursor sol: Weigh 0.1 g of polyvinylpyrrolidone (PVP) and 3.0 g of diammonium hydrogen phosphate ((NH4)2HPO4, ≥99%), dissolve them in 100 mL of anhydrous ethanol, and magnetically stir at 400 rpm for 24 h at 25 °C to form a uniform and transparent sol.

[0139] S5, Composite Hybridization and Solvent Evaporation: Add all of the SPE-NCM811 powder (approximately 10.0 g) obtained in step S3 to the above sol and continue magnetic stirring for 24 h to ensure uniform adsorption of the precursor; then place the entire system in an oil bath at 50°C and slowly evaporate the solvent ethanol until a non-flowing viscous slurry is formed.

[0140] S6. Vacuum sintering treatment: The viscous slurry was transferred to an alumina boat and then placed in a vacuum tube furnace. After the furnace was closed, a vacuum was drawn to -0.1 MPa using a mechanical pump, and then heated from room temperature to 450°C at a heating rate of 3°C / min. The furnace was then held at 450°C for sintering for 5 hours. Subsequently, the furnace was allowed to cool naturally to room temperature, and the product was removed to obtain the final H-SPE-NCM811 cathode material coated with an organic-inorganic hybrid solid polymer electrolyte.

[0141] Example 4: The final organic-inorganic hybrid solid polymer electrolyte-coated H-SPE-NCM811 cathode material core is a high-nickel cathode material NCM811; the organic-inorganic hybrid coating layer includes a ring-opening copolymer of maleic anhydride and 1,3-dioxolane, and Li3PO4 nanocrystals are in situ embedded in the ring-opening copolymer of maleic anhydride and 1,3-dioxolane; wherein, the particle size D50 of the high-nickel cathode material NCM811 is 5 μm; the thickness of the organic-inorganic hybrid coating layer is 30 nm; the molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 30000 g / mol; the content of the Li3PO4 nanocrystals accounts for 20% of the total mass of the organic-inorganic hybrid coating layer, and the particle size of the Li3PO4 nanocrystals is 15 nm.

[0142] Example 5: This embodiment provides a high-nickel cathode material (H-SPE-NCM811 cathode material) coated with an organic-inorganic hybrid solid polymer electrolyte. The H-SPE-NCM811 cathode material is prepared by the following steps: S1. Preparation of polymerization solution: In an argon-filled glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), take a dry 250 mL three-necked flask and add 100 mL of anhydrous 1,3-dioxolane (DOL, moisture ≤ 50 ppm); then, weigh 9.8 g (0.1 mol) maleic anhydride (MA, ≥ 99%) and add it to the flask; seal the three-necked flask and remove it from the glove box, place it on a magnetic stirrer, and stir at 500 rpm for 2 h at 25 °C until the maleic anhydride is completely dissolved, resulting in a clear and transparent homogeneous MA / DOL solution with a concentration of 1 M.

[0143] S2, in-situ open-ring copolymer coating: Reconnect the three-necked flask to the argon protection system; add 10.0 g of single-crystal LiNi to the solution. 0.8 Co 0.1 Mn 0.1 O2 (NCM811, D50=5μm) positive electrode material; then, the system was placed in an ultrasonic cell disruptor and ultrasonically treated for 30 min at 100 W under an argon atmosphere to fully disperse the NCM811 particles and activate their surface alkaline sites; after that, the ultrasonic treatment was removed and the reaction was continued at 25°C with magnetic stirring (300 rpm) for 5 h to allow MA and DOL to fully undergo ring-opening copolymerization on the NCM811 surface to form a preliminary coating layer of solid polymer electrolyte.

[0144] S3. Washing and drying: After the reaction was completed, the mixture was transferred to a centrifuge tube and centrifuged at 8000 rpm for 10 min to collect the solid product. The solid product was redispersed and washed with 50 mL of anhydrous 1,2-dimethoxyethane (DME, moisture ≤50 ppm). This process was repeated three times to completely remove unreacted monomers and free polymers. The washed solid product was placed in a vacuum drying oven and dried at 80 °C for 5 h to obtain SPE-NCM811 powder with SPE pre-coated surface.

[0145] S4. Preparation of inorganic hybrid precursor sol: Weigh 0.1 g of polyvinylpyrrolidone (PVP) and 1.0 g of diammonium hydrogen phosphate ((NH4)2HPO4, ≥99%), dissolve them in 100 mL of anhydrous ethanol, and magnetically stir at 400 rpm for 24 h at 25 °C to form a uniform and transparent sol.

[0146] S5, Composite Hybridization and Solvent Evaporation: Add all of the SPE-NCM811 powder (approximately 10.0 g) obtained in step S3 to the above sol and continue magnetic stirring for 24 h to ensure uniform adsorption of the precursor; then place the entire system in an oil bath at 50°C and slowly evaporate the solvent ethanol until a non-flowing viscous slurry is formed.

[0147] S6. Vacuum sintering treatment: The viscous slurry was transferred to an alumina boat and then placed in a vacuum tube furnace. After the furnace was closed, a vacuum was drawn to -0.1 MPa using a mechanical pump, and then heated from room temperature to 450°C at a heating rate of 3°C / min. The furnace was then held at 450°C for sintering for 5 hours. Subsequently, the furnace was allowed to cool naturally to room temperature, and the product was removed to obtain the final H-SPE-NCM811 cathode material coated with an organic-inorganic hybrid solid polymer electrolyte.

[0148] Example 5: The final organic-inorganic hybrid solid polymer electrolyte-coated H-SPE-NCM811 cathode material core is a high-nickel cathode material NCM811; the organic-inorganic hybrid coating layer includes a ring-opening copolymer of maleic anhydride and 1,3-dioxolane, and Li3PO4 nanocrystals are in situ embedded in the ring-opening copolymer of maleic anhydride and 1,3-dioxolane; wherein, the particle size D50 of the high-nickel cathode material NCM811 is 5 μm; the thickness of the organic-inorganic hybrid coating layer is 30 nm; the molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 30000 g / mol; the content of the Li3PO4 nanocrystals accounts for 5% of the total mass of the organic-inorganic hybrid coating layer, and the particle size of the Li3PO4 nanocrystals is 5 nm.

[0149] Example 6 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that single-crystal LiNi is used instead. 0.8 Co 0.1 Mn 0.1 The O2 (NCM811, D50=5 μm) cathode material was replaced with an equal mass of single-crystal LiNi. 0.5 Co 0.2 Mn 0.3 O2 (NCM523, D50=5 μm) cathode material; other steps are the same as in Example 1.

[0150] Example 7 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that single-crystal LiNi is used instead. 0.8 Co 0.1 Mn 0.1The O2 (NCM811, D50=5 μm) cathode material was replaced with an equal mass of single-crystal LiNi. 0.6 Co 0.2 Mn 0.2 O2 (NCM622, D50=5 μm) cathode material; other steps are the same as in Example 1.

[0151] Example 8 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Example 1 is that the molar ratio of maleic anhydride and 1,3-dioxolane is 1:8; the other steps are the same as in Example 1.

[0152] Example 9 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Example 1 is that the molar ratio of maleic anhydride and 1,3-dioxolane is 1:16; the other steps are the same as in Example 1.

[0153] Example 10 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that the magnetic stirring in S2 is adjusted to 2 h, so that the final thickness of the organic-inorganic hybrid coating layer is 20 nm; the other steps are the same as in Embodiment 1.

[0154] Example 11 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that the magnetic stirring in S2 is adjusted to 30 h, so that the final thickness of the organic-inorganic hybrid coating layer is 100 nm; the other steps are the same as in Embodiment 1.

[0155] Example 12 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that, in S5, magnetic stirring is continued at 20°C for 36 h, while the other steps are the same as in Embodiment 1.

[0156] Example 13 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that, in S5, magnetic stirring is continued at 30°C for 12 h, while the other steps are the same as in Embodiment 1.

[0157] Example 14 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that in S6, the material is heated from room temperature to 300°C at a heating rate of 2°C / min and sintered at 300°C for 8 hours. The other steps are the same as in Embodiment 1.

[0158] Example 15 This embodiment provides a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte. The only difference from Embodiment 1 is that, in SS6, the temperature is increased from room temperature to 500°C at a heating rate of 5°C / min, and then sintered at 500°C for 2 hours. The other steps are the same as in Embodiment 1.

[0159] Comparative Example 1 This comparative example provides a high-nickel cathode material, wherein the high-nickel cathode material is an uncoated single-crystal LiNi. 0.8 Co 0.1 Mn 0.1 O2 (NCM811, D50=5μm) cathode material.

[0160] Comparative Example 2 This comparative example provides a polymer-coated high-nickel cathode material, which differs from Example 1 only in that steps S4 to S6 are omitted. The polymer-coated high-nickel cathode material is SPE-NCM811 powder with SPE pre-coated on the surface, which is prepared in S3.

[0161] Comparative Example 3 This comparative example provides an inorganic-coated high-nickel cathode material, which differs from Example 1 only in that steps S1 to S3 are omitted, that is, the SPE-NCM811 powder in step S5 is directly replaced with an equal mass of uncoated single-crystal LiNi. 0.8 Co 0.1 Mn 0.1 O2 (NCM811, D50=5 μm) cathode material; the obtained high-nickel cathode material is NCM811 powder in situ coated with lithium phosphate.

[0162] Test case Test sample: The high-nickel cathode material with organic-inorganic hybrid solid polymer electrolyte coating provided in Examples 1-15, the high-nickel cathode material provided in Comparative Example 1, the polymer-coated high-nickel cathode material provided in Comparative Example 2, and the inorganic-coated high-nickel cathode material provided in Comparative Example 3.

[0163] Preparation of the positive electrode sheet and its all-solid-state battery: (1) Preparation of composite cathode slurry: In an argon-filled glove box (H2O < 0.1 ppm, O2 < 0.1 ppm), the components were precisely weighed according to the following mass ratios: active material: 75% of the above test samples, solid electrolyte; sulfide solid electrolyte Li6PS5Cl, 20%; binder: styrene-butadiene rubber (SEBs), 3%; conductive agent: vapor-grown carbon fiber (VGCF), 2%. First, the SEBs binder was dissolved in an appropriate amount of anisole mixed solvent (volume ratio 1:1, water < 100 ppm) to prepare a 5 wt.% SEBs solution. Then, the Li6PS5Cl solid electrolyte, VGCF conductive agent, and active material (the above test samples) were slowly added to the solution sequentially in a stirrer; stirring was continued for 12 h until a composite positive electrode slurry with moderate viscosity, uniformity, and no particles was formed; the solid content of the slurry was controlled at 60–70 wt.%.

[0164] (2) Coating and drying: Using a blade coater, the composite positive electrode slurry prepared in step (1) above was uniformly coated onto an aluminum foil current collector with a thickness of 20 μm. The wet film thickness was set to 450 μm. The coated electrode was then transferred to a vacuum drying oven and dried at 60°C for 12 h to gently evaporate the organic solvent and avoid damaging the solid electrolyte structure.

[0165] (3) Tableting and cutting: The dried electrode sheets were removed from the vacuum drying oven and cold-pressed at 100 MPa using a roller press under argon protection to improve the compaction density of the electrode and its adhesion to the current collector. Finally, the calendered electrode sheets were punched into circular sheets with a diameter of 10 mm, thus obtaining the composite positive electrode sheets of the corresponding embodiment or comparative example produced by the wet process. The surface loading of active material in each electrode sheet was weighed and calculated to be approximately 20 mg / cm². 2 .

[0166] (4) Assemble all-solid-state batteries: Battery assembly was completed in a glove box. A 10 mm PEEK mold was used, and 80 mg of Li6PS5Cl powder was added. The mold was pre-pressed at 200 MPa for 2 min to form an independent solid electrolyte membrane layer. Subsequently, the composite positive electrode sheet (active material side facing the electrolyte layer) obtained in step (3) was placed on the electrolyte layer. On the other side of the electrolyte layer, a 10 mm diameter and 100 μm thick indium sheet and a 6 mm diameter and 100 μm thick lithium sheet were placed sequentially as composite negative electrodes. After initial pressing at 50 MPa for 1 min, the mold was encapsulated, and an additional constant axial pressure of 50 MPa was applied to the encapsulated battery. Finally, the battery was assembled into an all-solid-state battery for performance testing.

[0167] Test conditions: Under constant temperature of 25 ℃, charge and discharge were performed at rates of 0.1C / 0.2C / 0.5C / 1C / 2C / 5C, and charge and discharge cycle tests were conducted with a charge and discharge cutoff voltage of 3.7 V~1.9 V.

[0168] The discharge specific capacity of each group of batteries at different rates is shown in Table 1 below: Table 1

[0169] The cycle retention rates of each battery group are shown in Table 2 below: Table 2

[0170] As shown in Tables 1 and 2, the H-SPE-NCM prepared through the examples exhibits excellent electrochemical performance. It forms a MA / DOL organic SPE coating layer on the surface of the positive electrode active material, overcoming the bottlenecks of high temperature, vacuum, and expensive equipment in existing technologies. Furthermore, it forms a coating layer with both flexibility and rigidity with phosphate, retaining the in-situ polymerization, flexibility, and Li... + Conductivity is improved to further enhance mechanical strength, thermal stability, and interface durability. The assembled sulfide-based solid-state battery solves the problems of continuously increasing interfacial impedance due to LPSCl oxidation under high voltage, the high rigidity and complex process of traditional inorganic coatings which are easily penetrated by cracks, and the narrow electrochemical stability window which can trigger electrochemical reduction reactions during battery cycling, leading to undesirable interfacial reduction byproducts, high electronic conductivity, grain boundary resistance, and voids and cracks. Ultimately, the overall performance of the battery is improved.

[0171] A comparison of Examples 1 and 2 shows that the only difference between them is the concentration of the MA / DOL solution. Example 1 uses the optimal concentration of 1 M, while Example 2 uses 0.8 M, with all other conditions remaining the same. After the concentration was reduced, the battery's discharge specific capacity increased slightly at low rates, but the capacity decay was more pronounced at medium and high rates, with a significant difference at 5C. The cycle retention rate also showed a decreasing trend, dropping from 86% to 77% after 500 cycles. This indicates that the MA / DOL concentration is crucial for coating formation; a suitable concentration can construct a better coating structure, improving the material's rate performance and long-cycle stability, while a lower concentration weakens the coating effect.

[0172] A comparison of Examples 1 and 3 shows that the only difference between them is the concentration of the MA / DOL solution. Example 1 uses an optimal concentration of 1 M, while Example 3 increases the concentration to 1.2 M, with all other conditions remaining the same. With the increased concentration, the discharge specific capacity of the battery decreased at all rates, with more significant degradation at medium and high rates. The cycle retention rate also decreased slightly, dropping from 86% to 81% after 500 cycles. This indicates that a higher MA / DOL concentration is not always better; excessively high concentrations can affect the uniformity of the coating layer and ion transport efficiency. A suitable concentration can balance the coating effect and electrochemical performance, while excessively high concentrations weaken the rate performance and cycle stability of the material.

[0173] A comparison of Examples 1 and 4 shows that the only difference between them is the phosphate concentration. Example 1 uses an optimal concentration of 2 wt.%, while Example 4 increases it to 3 wt.%, with all other conditions remaining the same. With the increased concentration, the specific capacity of the battery decreased at all discharge rates, with more significant degradation at medium and high rates. The cycle retention rate increased slightly after 100 and 300 cycles, but significantly decreased to 79% after 500 cycles. This indicates that excessively high phosphate concentrations disrupt the "rigid-flexible balance" of the coating layer. Although short-term cycle stability may slightly improve, long-term performance degradation is easily caused by impaired ion transport. 2 wt.% is a suitable concentration that balances performance.

[0174] A comparison of Examples 1 and 5 shows that the only difference between them is the phosphate concentration. Example 1 uses an optimal concentration of 2 wt.%, while Example 5 reduces it to 1 wt.%, with all other conditions remaining the same. After the concentration was reduced, the battery's specific capacity at low-rate discharge increased slightly, but the capacity decay at medium and high rates was more pronounced; the overall cycle retention rate decreased, with the 500-cycle retention rate dropping from 86% to 80%. This indicates that excessively low phosphate concentrations weaken the rigid support and physical barrier function of the coating layer, making it difficult to maintain a "rigid-flexible balance." 2 wt.% is a suitable concentration that balances ion transport and interfacial stability.

[0175] A comparison of Examples 1 and 6-7 shows that when the base material is replaced with NCM523 and NCM622 respectively, the discharge specific capacity of both is reduced at all rates compared to NCM811 in Example 1, with a significant difference at the 5C high rate. Regarding cycle retention, Example 1 has a 500-cycle retention rate of 86%, which is also better than the 81% of Example 6 and 79% of Example 7. This indicates that the hybrid coating system is more compatible with NCM811 and can better leverage the capacity advantages of high-nickel materials, while NCM523 and NCM622 are less likely to release their modification effects.

[0176] As can be seen from the comparison between Examples 1 and Examples 8-9, compared with Example 1, the discharge specific capacity of Examples 8-9 at all rates is significantly reduced, with the attenuation being particularly severe at the high rate of 5C. The 5C capacity of Example 9 is only 40.2 mAh·g. -1The cycle retention rate also declined significantly, with the retention rate after 500 cycles dropping to 50% in Example 8 and only 18% in Example 9, far lower than the 86% in Example 1. This demonstrates that the molar ratio is crucial for constructing a high-quality coating; deviations will severely damage the coating structure and significantly weaken the material's electrochemical performance.

[0177] A comparison of Examples 1 and 10-11 shows that the coating thicknesses of Examples 10-11 are 20 nm and 100 nm, respectively, deviating from the optimal value of 30 nm in Example 1. The discharge specific capacity at all rates in both Examples 10-11 is lower than that in Example 1, with more significant attenuation at higher rates. Cycle retention also declines sharply, with a retention rate of only 59% after 500 cycles, far lower than the 86% in Example 1. This demonstrates that the coating thickness needs to be appropriately matched; too thin a coating results in incomplete coverage, while too thick a coating hinders ion transport, both severely weakening the rate and cycle performance of the material.

[0178] A comparison of Examples 1 and 12-13 shows that the hybridization parameters of Examples 12-13 deviate from the preferred range. The discharge specific capacity at all rates in both examples is lower than that of Example 1, with more significant high-rate decay and a decline in cycle retention, far lower than that of Example 1. This demonstrates that the temperature and time parameters of the hybridization need to be precisely controlled; deviations can lead to uneven precursor adsorption, coating layer structure failure, and severely weakened electrochemical performance.

[0179] A comparison of Examples 1 and 14-15 shows that the sintering parameters of Examples 14-15 deviated from the preferred range. The discharge specific capacity at all rates in both examples was significantly lower than that of Example 1, with particularly noticeable degradation at high rates. Cycle retention also declined sharply, far below the 86% of Example 1. This demonstrates that precise control of sintering temperature and time is crucial; deviations can lead to poor Li3PO4 crystal morphology, poor coating layer bonding, and severe degradation of electrochemical performance.

[0180] A comparison of Example 1 and Comparative Example 1 reveals that the core difference lies in the coating process: Example 1 uses an organic-inorganic hybrid coating on its high-nickel cathode material, while Comparative Example 1 uses the uncoated raw material. All other conditions remain the same. After coating, the battery's discharge specific capacity at all rates is significantly improved, with a particularly noticeable difference at 5C. Cycle retention is also greatly optimized, increasing from 5% to 86% after 500 cycles. This demonstrates that the hybrid coating effectively suppresses interfacial side reactions, reduces impedance, adapts to volume changes, and significantly improves the material's rate performance and long-cycle stability, overcoming the inherent defects of the uncoated material.

[0181] A comparison of Example 1 and Comparative Example 2 reveals that the core difference lies in the coating process: Example 1 uses an organic-inorganic hybrid coating, while Comparative Example 2 uses only a single polymer coating, with all other conditions remaining the same. After hybrid coating, the battery's discharge specific capacity at all rates significantly improved, with a particularly noticeable difference at 5C rate; cycle retention was also significantly optimized, increasing from 60% to 86% after 500 cycles. This demonstrates that the "rigid-flexible" coating layer formed by introducing an inorganic phase can more effectively suppress interfacial side reactions, improve mechanical strength and ion transport efficiency, compensate for the performance shortcomings of a single organic coating layer, and significantly enhance the electrochemical performance of the material.

[0182] A comparison of Example 1 and Comparative Example 3 shows that Example 1 uses an organic-inorganic hybrid coating, while Comparative Example 3 uses a single inorganic coating. Compared to Example 3, Example 1 exhibits significantly higher discharge specific capacity at all rates, with the difference being particularly pronounced at medium to high rates. At 5C, Example 1 reaches 153.7 mAh·g. -1 Comparative Example 3 has only 74.8 mAh·g -1 The hybrid coating demonstrates that its ion transport efficiency is far superior to that of a single inorganic coating. Furthermore, in terms of cycle retention, Example 1 showed significantly higher retention rates at 100, 300, and 500 cycles compared to Comparative Example 3; at 500 cycles, Example 1 still maintained 86%, while Comparative Example 3 only achieved 8%. This indicates that the high rigidity of a single inorganic coating layer makes it unsuitable for adapting to the volume changes of the high-nickel cathode, easily leading to cracking and severe interfacial side reactions. In contrast, the hybrid coating, combining rigidity and flexibility, can suppress cracks, stabilize the interface, and balance ion transport and structural stability, thus significantly improving electrochemical performance.

[0183] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte, characterized in that, include: The core and the organic-inorganic hybrid coating layer covering the surface of the core; The core is a high-nickel cathode material; the organic-inorganic hybrid coating layer includes a ring-opening copolymer of maleic anhydride and 1,3-dioxolane, and Li3PO4 nanocrystals are in situ embedded in the ring-opening copolymer of maleic anhydride and 1,3-dioxolane.

2. The high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte according to claim 1, characterized in that, The chemical formula of the high-nickel cathode material is LiNi. x Co y Mn z O2; where 0.80≤x≤0.96, 0.05≤y≤0.20, 0.05≤z≤0.20; Preferably, the particle size D50 of the high-nickel cathode material is 3.0~5.0 μm.

3. The high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte according to claim 1, characterized in that, The molar ratio of maleic anhydride to 1,3-dioxolane is 1:(9~15); Preferably, the molecular weight of the ring-opening copolymer of maleic anhydride and 1,3-dioxolane is 20,000 to 50,000 g / mol; Preferably, the thickness of the organic-inorganic hybrid coating layer is 20~100 nm; Preferably, the content of the Li3PO4 nanocrystals accounts for 5-20% of the total mass of the organic-inorganic hybrid coating layer; Preferably, the Li3PO4 nanocrystals have a particle size of 5~20 nm.

4. A method for preparing a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte according to any one of claims 1 to 3, characterized in that, The preparation method includes: Maleic anhydride and 1,3-dioxolane were mixed to obtain a homogeneous MA / DOL solution; The high-nickel cathode material was dispersed in the homogeneous MA / DOL solution and subjected to in-situ ring-opening copolymerization to obtain SPE-NCM powder. Polyvinylpyrrolidone, phosphate and solvent are mixed to obtain inorganic hybrid precursor sol; The SPE-NCM powder was placed in the inorganic hybrid precursor sol, and after composite hybridization, the solvent was removed to obtain a slurry. The slurry is sintered to obtain the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte.

5. The method for preparing the high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte according to claim 4, characterized in that, The molar ratio of maleic anhydride to 1,3-dioxolane is 1:(9~15); the concentration of the homogeneous MA / DOL solution is 0.8~1.2 M; Preferably, the preparation of the homogeneous MA / DOL solution is carried out under an inert atmosphere. Preferably, the mass-to-volume ratio of the high-nickel cathode material to the homogeneous MA / DOL solution is 1.0 g:(5~15) mL; Preferably, the dispersion is ultrasonic dispersion; wherein the ultrasonic dispersion power is 100~300 W, and the ultrasonic dispersion time is 10~60 min; Preferably, the in-situ ring-opening copolymerization reaction is carried out under stirring conditions; the temperature of the in-situ ring-opening copolymerization reaction is 20~30℃, and the time of the in-situ ring-opening copolymerization reaction is 3~12 h. Preferably, the dispersion and the in-situ ring-opening copolymerization reaction are carried out under an inert atmosphere.

6. The method for preparing the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte according to claim 4, characterized in that, The following post-processing steps are included after the in-situ ring-opening copolymerization reaction is completed: The mixture after the in-situ ring-opening copolymerization reaction was centrifuged to collect the solid product; the solid product was washed; the washed product was dried to obtain the SPE-NCM powder. Preferably, the centrifugal separation speed is 6000~10000 rpm; Preferably, the washing reagent is 1,2-dimethoxyethane; Preferably, the drying is carried out under vacuum conditions, the drying temperature is 60~100℃, and the drying time is 2~10 h.

7. The method for preparing the high-nickel cathode material coated with the organic-inorganic hybrid solid polymer electrolyte according to claim 4, characterized in that, The inorganic hybrid precursor sol comprises, by mass percentage: 0.1-1% polyvinylpyrrolidone, 1-3% phosphate, and the remainder is solvent; Preferably, the phosphate is diammonium hydrogen phosphate; Preferably, the solvent is ethanol; Preferably, the mixing process for preparing the inorganic hybrid precursor sol is carried out under stirring conditions; the mixing temperature is 20~30℃, and the mixing time is 12~36 h. Preferably, the composite hybridization is carried out under stirring conditions; the temperature of the composite hybridization is 20~30℃, and the time of the composite hybridization is 12~36 h; Preferably, the solvent removal is performed by water bath evaporation; the temperature of the water bath evaporation is 40~60℃. Preferably, the heating rate of the sintering treatment is 2~5℃ / min, the sintering temperature is 300~500℃, and the sintering time is 2~8 h; Preferably, the sintering process is carried out under a vacuum and / or an inert atmosphere.

8. The application of a high-nickel cathode material coated with an organic-inorganic hybrid solid polymer electrolyte according to any one of claims 1 to 3 in the preparation of cathode sheets and / or sulfide all-solid-state lithium batteries.

9. A positive electrode plate, characterized in that, The positive electrode sheet comprises a high-nickel positive electrode material coated with an organic-inorganic hybrid solid polymer electrolyte as described in any one of claims 1 to 3; And / or, the positive electrode further includes: a sulfide solid electrolyte, a binder, and conductive carbon.

10. A sulfide-based all-solid-state lithium battery, characterized in that, The sulfide all-solid-state lithium battery includes the positive electrode as described in claim 9.

Images