A self-repairing sulfide composite solid electrolyte membrane and a full solid-state battery

Abstract

The application belongs to the technical field of solid-state lithium batteries, and discloses a self-repairing sulfide composite solid electrolyte film, a preparation method and application. The film comprises a sulfide solid electrolyte and a self-repairing ion conductive binder phase; the binder phase contains a polymer framework with a coordination unit, a fluorine-containing polar unit and a flexible chain segment, a dynamic coordination salt, and optionally a lithium salt or an ionic liquid. The coordination unit forms a dynamic coordination bond with metal ions, the fluorine-containing polar unit forms a dynamic interaction with the lithium salt or the ionic liquid, and an ion conductive network that can be rearranged is constructed on the surface of sulfide particles and between the particles. The sulfide particles act as a rigid framework and a repair fulcrum, can limit crack propagation and promote the enrichment of the binder phase and the dynamic bond recombination, repair micro-cracks and interface gaps, relieve stress concentration, and maintain ion transmission. The electrolyte film has film-forming property, flexibility, interface compatibility and electrochemical stability, and can be used in a full solid-state lithium battery.

Description

Technical Field

[0001] This invention belongs to the field of all-solid-state lithium battery technology, specifically relating to a self-healing sulfide composite solid electrolyte membrane, its preparation method, and its application in solid-state batteries. More specifically, this invention relates to a self-healing composite solid electrolyte membrane and an all-solid-state battery obtained by introducing a double dynamic bond ion-conducting binder phase on the surface of sulfide solid electrolyte particles and at the particle interface. This invention relates to a composite solid electrolyte membrane in which a self-healing ion-conducting binder phase and sulfide ceramic particles jointly construct a dynamic interface coupling layer. The sulfide ceramic particles not only undertake the main function of inorganic ion conduction but also act as a participating and reinforcing phase in dynamic repair, synergistically improving crack repair, particle reconnection, and interface stability. Background Technology

[0002] All-solid-state lithium batteries are considered an important development direction for next-generation high-energy-density energy storage devices due to their high safety, high energy density, and wide temperature range application potential. Solid-state electrolytes, as the core functional material of all-solid-state lithium batteries, not only determine the lithium-ion migration efficiency but also directly affect the stability of the electrode / electrolyte interface, cycle life, and rate performance.

[0003] Among existing solid electrolyte systems, sulfide solid electrolytes have attracted widespread attention due to their high room-temperature ionic conductivity, good cold-pressing formability, and low interfacial impedance with electrodes. However, pure sulfide solid electrolytes still have significant drawbacks. On the one hand, sulfide materials themselves are relatively brittle, and microcracks are easily formed during film formation, transfer printing, and lamination. On the other hand, during assembly, stacking, and charge-discharge cycling, localized decontamination, void expansion, and stress concentration can easily occur between particles and at the electrode / electrolyte interface, leading to interruption of ion pathways, increased interfacial impedance, and cycle degradation.

[0004] To improve the processability and mechanical integrity of sulfide electrolyte membranes, existing technologies typically employ low glass transition temperature polymers, common binders, or in-situ polymerized monomers to composite modify the sulfide electrolyte. While these strategies can improve film formation and flexibility in the initial state, most are static bonding or static network reinforcement methods, making it difficult to continuously repair newly formed microcracks and interfacial voids during subsequent pressure, bending, and cycling. Therefore, they cannot fundamentally solve the dynamic failure problem of sulfide composite electrolyte membranes.

[0005] On the other hand, self-healing polymer electrolytes or ion gels, by introducing dynamic non-covalent interactions, can, to some extent, balance network rearrangement, damage repair, and ion transport. Specifically, reversible metal-ligand coordination can construct a strong dynamic network, while ion-dipole interactions are beneficial for regulating chain segment movement and the ion transport environment. Introducing both synergistically can potentially improve the material's mechanical support, self-healing ability, and ion-conducting properties simultaneously.

[0006] However, existing research on polymer-modified sulfide solid electrolytes often treats the polymer phase as an inert binder or flexible filler, primarily limiting its role to initial film formation and mechanical buffering, with less consideration given to the dynamic interfacial coupling between the polymer phase and the sulfide ceramic phase. In fact, sulfide ceramic particles are not only the main ion transport components but also crucial interfacial phases influencing polymer network rearrangement, self-healing pathways, and crack evolution. If there is a lack of effective interaction between the binder phase and the sulfide particles, the dynamic network struggles to stably accumulate on the particle surface and at the crack tip, and the repair effect is often limited to the polymer itself, making it difficult to achieve particle reconnection and ion pathway reconstruction in the composite film.

[0007] Furthermore, the polar sites, surface energy differences, Lewis acid-base characteristics, and interparticle confinement space on the surface of sulfide particles can all significantly influence the local enrichment of dynamic bonds, the directional migration of chain segments, and the interfacial reconstruction during the repair process. If the interfacial adsorption and confinement effects between the sulfide ceramic particle surface and the self-healing binder phase can be rationally utilized, it is possible not only to improve the distribution efficiency of the binder phase in key interfacial regions but also to leverage the rigid framework of the sulfide particles to limit crack opening width and provide bridging supports, thereby amplifying the dynamic repair effect and enhancing the structural stability after repair.

[0008] Therefore, developing a self-healing bonding system capable of constructing dynamic ion-conducting bridging phases on the surface and at the interparticle interfaces of sulfide particles, and applying it to the preparation of sulfide composite solid electrolyte membranes with high inorganic content, good film-forming properties, interfacial stability, and self-healing capabilities, is of great significance. In particular, it is necessary to construct a dynamic interfacial repair system involving both a binder phase and sulfide ceramics, transforming sulfide ceramic particles from passive fillers into dynamic repair participants and reinforcing phases. Summary of the Invention

[0009] (a) Purpose of the invention The purpose of this invention is to provide a self-healing sulfide composite solid electrolyte membrane, its preparation method, and its application, to solve the problems of existing sulfide composite solid electrolyte membranes easily generating microcracks, degrading interparticle contacts, and expanding and difficult-to-recover interfacial voids during preparation and cycling. This invention further aims to construct a dynamic interfacial coupling repair system composed of a self-healing ion-conducting binder phase and sulfide ceramics, enabling the sulfide ceramic particles to simultaneously function as an inorganic ion-conducting host, a rigid supporting framework, and a dynamically repairing reinforcing phase in the composite membrane.

[0010] (II) Technical Solution To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a self-healing sulfide composite solid electrolyte membrane. The composite solid electrolyte membrane uses a sulfide solid electrolyte as the main phase and a self-healing ion-conductive binder phase as the auxiliary phase. The self-healing ion-conductive binder phase is composed of a polymer backbone having coordination units, fluorine-containing polar units, and flexible segment units, a dynamic coordination salt, and optionally a lithium salt and / or an ionic liquid.

[0011] The coordination unit forms a first dynamic bond with metal ions in the dynamic coordination salt to construct a high-strength dynamic network capable of reversible rearrangement. The fluorine-containing polar unit forms a second dynamic interaction with ions in the lithium salt and / or ionic liquid to regulate polymer chain movement, improve the local ion transport environment, and promote interfacial compatibility. These two dynamic interactions synergistically construct a rearrangeable ion-conducting network, allowing the binder phase to preferentially distribute on the surface of sulfide particles and in the particle contact area. This enables crack closure, contact recovery, and ion pathway reconstruction after mechanical damage to the composite film.

[0012] The key to this invention lies not in introducing a single self-healing binder, but in constructing a dynamic interface repair system involving a sulfide ceramic phase. The self-healing ion-conductive binder phase forms a dynamic bridging layer on the surface of sulfide particles and at the particle interfaces. The coordination units of the polymer skeleton form a reversible coordination network with the dynamic coordination salt, and the fluorine-containing polar units form reversible ion-dipole interactions with the ions in the system. Simultaneously, one or more of the following interactions—interfacial adsorption, Lewis acid-base interaction, polar interaction, electrostatic interaction, and mechanical interlocking—between the sulfide ceramic particle surface and the binder phase preferentially enrich the dynamic bonds in the particle interface region. After damage, the fresh fracture surface of the sulfide particles can induce the redistribution and reconstruction of the binder phase at the crack tip and in the particle decontamination area. The sulfide particles themselves, acting as a rigid supporting skeleton and bridging fulcrum, can also inhibit excessive crack opening and shorten the migration distance of the dynamic network across the crack, thereby amplifying the dynamic repair effect of the binder phase and achieving crack closure, particle reconnection, and ion pathway restoration.

[0013] In a preferred embodiment, the self-healing ion-conductive binder phase is not uniformly and randomly distributed throughout the composite film, but rather preferentially enriched on the surface of sulfide particles, in particle contact areas, and along potential crack propagation paths, thereby forming a continuous or quasi-continuous dynamic interface coupling layer. This dynamic interface coupling layer can maintain effective connections between inorganic particles and can also respond rapidly and complete local structural rearrangement after damage occurs.

[0014] In a preferred embodiment, the polymer backbone can be constructed through a generalized design of fluorinated polar units, coordination units, flexible segment units, and optional crosslinking units. It can be constructed using random copolymerization, block copolymerization, graft copolymerization, or an interpenetrating network structure.

[0015] In a preferred embodiment, the polymer backbone satisfies the following general formula (I): P = Poly[xA + yB + Zc + wD] Wherein, A is a fluorinated polar unit, preferably derived from fluorinated acrylates, fluorinated methacrylates, fluorinated vinyl ethers, trifluoromethyl arylethylene, etc.; B is a coordination unit, preferably derived from vinylimidazole, allylimidazole, vinylpyridine, vinyltriazole, benzimidazole-derived vinyl monomers, etc.; C is a flexible segment unit, preferably derived from low Tg acrylates, polyether side chains, polycarbonate segments, polysiloxane segments, butadiene segments, isoprene segments, etc.; D is an optional crosslinking or branching unit, preferably derived from diacrylates, triacrylates and their derivatives.

[0016] In a preferred embodiment, the dynamic coordination salt is one or more selected from Zn(TFSI)2, Zn(OTf)2, Mg(TFSI)2, Mg(OTf)2, Al(OTf)3, Ca(TFSI)2, ZnCl2, CuCl2, MgCl2, and AlCl3; the lithium salt is one or more selected from LiFSI, LiTFSI, LiDFOB, LiBOB, LiPF6, and LiBF4; and the ionic liquid is one or more selected from imidazolium, pyrrolidineonium, piperidinium, or quaternary ammonium salt fluorine-containing anionic ionic liquids.

[0017] In a preferred embodiment, the sulfide solid electrolyte is one or more of Argyrodite type, Thio-LISICON type, or thiophosphate glass / glass-ceramic electrolyte, preferably Li6PS5Cl, Li6PS5Br, Li6PS5I, Li3PS4, Li7P3S11, or Li 10 GeP2S 12 Li2S-P2S5 glass or glass ceramic.

[0018] The present invention also provides a method for preparing the above-mentioned self-healing sulfide composite solid electrolyte membrane, including steps such as polymer skeleton preparation, dynamic coordination network construction, sulfide particle refinement, composite slurry preparation, casting film formation and pressing densification.

[0019] The present invention also provides an all-solid-state lithium battery comprising the above-described composite solid-state electrolyte membrane.

[0020] (III) Beneficial Effects Compared with the prior art, the present invention has at least the following beneficial effects: This invention does not rely on a single static binder, but rather constructs a self-healing ion-conductive binder phase through the synergistic construction of a first dynamic bond and a second dynamic interaction, thereby achieving dynamic repair of the composite film while maintaining a high inorganic content.

[0021] The sulfide ceramic particles in this invention are not inert fillers, but rather serve as participating and reinforcing phases for dynamic repair. The interfacial coupling between the sulfide particle surface and the binder phase facilitates the enrichment of dynamic bonds on the particle surface and in the interparticle region, enabling crack repair to preferentially occur at the interface locations most critical for ion transport.

[0022] The sulfide ceramic particles in this invention can act as rigid bridging supports to limit the crack opening width, and shorten the migration and rearrangement distance of the binder phase through capillary channels and confined spaces between particles, thereby promoting the rapid reconstruction of dynamic coordination bonds and ion-dipole interactions, improving the repair efficiency of the composite film and the interface stability after repair.

[0023] By synergistically designing fluorinated polar units, coordination units, and flexible segment units, mechanical support, self-healing ability, interfacial compatibility, and ion transport performance can be balanced, reducing the risk of a significant decrease in the ion-conducting ability of the inorganic host due to excessive introduction of traditional polymers.

[0024] Since the fresh fracture surface of sulfide particles can induce the redistribution of self-healing ion-conductive bonding phase at the crack tip and particle decontamination area, the composite film obtained by the present invention can not only achieve self-repair of the polymer network after being cut, crushed or cyclically induced damage, but also achieve rebridging between inorganic particles and reconstruction of ion pathways.

[0025] The composite solid electrolyte membrane obtained by this invention can be applied to thin film forming, transfer printing and lamination processes, and is suitable for high-safety, high-capacity and high-energy-density all-solid-state lithium batteries. Attached Figure Description

[0026] Figure 1 The stress-strain curves of the composite solid electrolyte membrane before and after self-healing are shown in the example.

[0027] Figure 2 This is a cross-sectional morphology diagram of the composite solid electrolyte membrane in the embodiment.

[0028] Figure 3 The AC impedance spectra of the composite solid electrolyte membrane before and after repair are shown in the example.

[0029] Figure 4 The diagram shows the cycling performance of the Li|composite solid electrolyte membrane|Li symmetric battery in the example.

[0030] Figure 5 The diagram shows the cycle performance of the LFP||composite solid electrolyte membrane||Li battery in the embodiment.

[0031] Figure 6 The graph shows the cycle performance of the all-solid-state lithium battery NCM811||composite solid-state electrolyte membrane||Li in the example. Detailed Implementation

[0032] The present invention will be further illustrated below with reference to some comparative examples and embodiments. It should be noted that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Example

[0033] Trifluoroethyl methacrylate, 1-vinylimidazolium and n-butyl acrylate were dissolved in an anhydrous organic solvent at a monomer molar ratio of 60:10:30. An azo radical initiator was added, and the mixture was reacted at 70–85 °C for 8–12 h under nitrogen protection to obtain polymer backbone P1.

[0034] The polymer backbone P1 was dissolved in anhydrous acetonitrile, and Zn(TFSI)2 was added and stirred for 4 h to form a reversible coordination network between Zn²⁺ and the imidazole coordination sites in the polymer backbone. LiFSI was then added and stirring was continued to obtain a self-healing ion-conductive binder phase precursor solution.

[0035] Li6PS5Cl was ball-milled at 400 rpm for 10 h under an argon atmosphere, and then mixed and dispersed with the precursor solution for 60 min to obtain a composite slurry. The composite slurry was cast onto the surface of a PET release film, gradually dried at 60 °C, and then cold-pressed at 200 MPa after demolding to obtain a self-healing sulfide composite solid electrolyte membrane.

[0036] Based on the total mass of the membrane, the content of Li6PS5Cl is 92 wt%, the content of polymer backbone P1 is 5 wt%, the content of Zn(TFSI)2 is 2 wt%, and the content of LiFSI is 1 wt%. The target thickness of the prepared membrane is 50–80 μm.

[0037] The composite solid electrolyte membrane obtained in this embodiment and the battery assembled using this membrane are accompanied by the corresponding instruction manual. Figures 1-6 .

[0038] Trifluoroethyl methacrylate, 1-vinylimidazolium and n-butyl acrylate were free radical copolymerized at a monomer molar ratio of 75:5:20 to obtain polymer backbone P2.

[0039] Based on the total mass of the membrane, 98 wt% Li6PS5Cl, 1.2 wt% polymer backbone P2, 0.5 wt% Zn(TFSI)2, and 0.3 wt% LiFSI were composited. Li6PS5Cl was ball-milled at 500 rpm for 15 h, the composite slurry was dried at 60 °C, and pressed at 300 MPa to obtain a composite solid electrolyte membrane with a thickness of 30–50 μm.

[0040] Hexafluorobutyl methacrylate, 4-vinylpyridine, polyethylene glycol methacrylate and polyethylene glycol diacrylate were copolymerized at a monomer molar ratio of 45:15:30:10 to obtain a polymer backbone P3 containing crosslinking units.

[0041] Based on the total mass of the membrane, 80 wt% Li6PS5Cl, 12 wt% polymer backbone P3, 5 wt% Zn(TFSI)2 and 3 wt% LiTFSI were composited. Li6PS5Cl was ball-milled at 300 rpm for 8 h, the slurry was dried at 50 °C and pressed at 100 MPa to obtain a composite solid electrolyte membrane with a thickness of 80–120 μm.

[0042] The polymer backbone P4 is composed of trifluoromethylarylethylene units, vinylbenzimidazole units, and polycaprolactone flexible segment units, with a molar ratio of 94:1:5.

[0043] Based on the total mass of the membrane, 90 wt% Li6PS5Br, 7 wt% polymer backbone P4, 2 wt% Zn(OTf)2 and 1 wt% LiFSI were composited. Li6PS5Br was ball-milled at 450 rpm for 10 h, the slurry was dried at 60 °C and pressed at 250 MPa to obtain a composite solid electrolyte membrane with a thickness of 60–80 μm.

[0044] The polymer backbone P5 is composed of fluoromethacrylate units, vinyltriazole units, polysiloxane flexible segment units, and trimethylolpropane triacrylate crosslinking units in a molar ratio of 20:30:30:20.

[0045] Based on the total mass of the membrane, 85 wt% Li₂S-P₂S₅ glass ceramic, 9 wt% polymer backbone P₅, 4 wt% Mg(TFSI)₂, and 2 wt% LiTFSI were composited. The sulfides were ball-milled at 350 rpm for 12 h, the slurry was dried at 50 °C, and pressed at 150 MPa to obtain a composite solid electrolyte membrane with a thickness of 80–100 μm.

[0046] The polymer backbone P6 is composed of fluorinated vinyl ether units, vinyltriazole units, polysiloxane flexible segment units, and polyethylene glycol diacrylate units in a molar ratio of 55:10:30:5.

[0047] Based on the total mass of the membrane, 94 wt% Li6PS5Cl, 3.5 wt% polymer backbone P6, 1 wt% Zn(OTf)2, 0.5 wt% LiFSI, and 1 wt% pyrrolidineonium-based ionic liquid were composited. Li6PS5Cl was ball-milled at 600 rpm for 7 h, the slurry was dried at 40 °C, and pressed at 300–400 MPa to obtain composite solid electrolyte membranes with a thickness of 10–30 μm.

[0048] The polymer backbone P7 is composed of trifluoromethylarylethylene units, 4-vinylpyridine units and polyether flexible segment units in a molar ratio of 50:15:35.

[0049] Based on the total mass of the membrane, 88 wt% of Li7P3S 11 A composite of 8 wt% polymer backbone P7, 2.5 wt% Mg(TFSI)2, and 1.5 wt% LiTFSI. Li7P3S 11 The slurry was ball-milled at 200 rpm for 20 h, dried at 25–40 °C, and pressed at 50 MPa to obtain a composite solid electrolyte membrane with a thickness of 180–200 μm.

[0050] The polymer backbone P8 is composed of fluorinated polyether methacrylate units, vinylbenzimidazole units and polycarbonate flexible segment units in a molar ratio of 50:10:40.

[0051] Based on the total mass of the membrane, 95 wt% Li 10 GeP2S 12 A composite of 3.5 wt% polymer backbone P8, 0.8 wt% Al(OTf)3 and 0.7 wt% LiDFOB was prepared. The sulfide was ball-milled at 400 rpm for 12 h, the slurry was dried at 50 °C and pressed at 200 MPa to obtain a composite solid electrolyte membrane with a thickness of 60–80 μm.

[0052] The polymer backbone P9 is composed of hexafluorobutyl methacrylate units, 1-vinylimidazole units, polycaprolactone flexible segment units, and polyethylene glycol diacrylate units in a molar ratio of 40:20:35:5.

[0053] Based on the total mass of the membrane, 85 wt% Li3PS4, 10 wt% polymer backbone P9, 3 wt% Ca(TFSI)2 and 2 wt% LiBOB were composited. Li3PS4 was ball-milled at 300 rpm for 15 h, the slurry was dried at 50 °C and pressed at 150 MPa to obtain a composite solid electrolyte membrane with a thickness of 100–120 μm.

[0054] The polymer backbone P10 is composed of trifluoromethylarylethylene units, vinyltriazole units, polybutadiene flexible segment units, and trimethylolpropane triacrylate units in a molar ratio of 45:15:35:5.

[0055] Based on the total mass of the membrane, 90 wt% Li9 was used. 54 Si1. 74 P1. 44 S 11 A composite of 0.7Cl0.3, 7 wt% polymer backbone P10, 2 wt% Zn(TFSI)2, and 1 wt% LiFSI was prepared. The sulfide was ball-milled at 500 rpm for 7 h, the slurry was dried at 60 °C, and pressed at 250 MPa to obtain a composite solid electrolyte membrane with a thickness of 40–60 μm.

[0056] Except for the omission of Zn(TFSI)2 and the supplementation of the missing 2 wt% with polymer backbone P1, the types, proportions, and preparation conditions of the other raw materials were the same as in Example 1. Based on the total mass of the membrane, the Li6PS5Cl content was 92 wt%, the polymer backbone P1 content was 7 wt%, and the LiFSI content was 1 wt%.

[0057] In Example 1, trifluoroethyl methacrylate was replaced with an equimolar amount of methyl methacrylate, while the composition of other raw materials and preparation conditions were the same as in Example 1, in order to investigate the influence of fluorine-containing polar units and the second dynamic interaction on interfacial coupling and self-healing behavior.

[0058] Ordinary n-butyl polyacrylate was used as the static binder, and no dynamic coordination salt was added. Based on the total mass of the membrane, the Li6PS5Cl content was 92 wt%, the static polymer content was 7 wt%, and the LiFSI content was 1 wt%; the remaining ball milling, mixing, drying, and pressing conditions were the same as in Example 1.

[0059] The raw material composition is the same as in Example 1, but instead of coordinating the polymer backbone P1 with Zn(TFSI)2 beforehand, the polymer backbone P1, Zn(TFSI)2, LiFSI and Li6PS5Cl are directly mixed, and then a film is formed according to the conditions of Example 1.

[0060] Based on the total mass of the membrane, 99 wt% Li6PS5Cl, 0.6 wt% polymer backbone P1, 0.3 wt% Zn(TFSI)2 and 0.1 wt% LiFSI were composited, and the remaining preparation conditions were the same as in Example 1.

[0061] Based on the total mass of the membrane, 75 wt% Li6PS5Cl, 15 wt% polymer backbone P1, 6 wt% Zn(TFSI)2 and 4 wt% LiFSI were composited, and the remaining preparation conditions were the same as in Example 1.

Claims

1. A self-healing sulfide composite solid electrolyte membrane, characterized in that, The composite solid electrolyte membrane comprises, by total mass, 80 wt% to 98 wt% of sulfide solid electrolyte and 2 wt% to 20 wt% of self-healing ion-conductive binder phase; The self-healing ion-conductive binder phase includes a polymer framework, a dynamic coordination salt, and lithium salts and / or ionic liquids. The polymer backbone includes fluorinated polar units, coordination units, and flexible segment units. The coordination units form a first dynamic bond with the metal ions in the dynamic coordination salt, and the fluorinated polar units form a second dynamic interaction with the ions in the lithium salt or ionic liquid. The self-healing ion-conductive bonding phase is distributed on the surface and / or interparticle interface of the sulfide solid electrolyte particles and forms a dynamic interface coupling layer with the sulfide solid electrolyte particles. After the composite solid electrolyte membrane is damaged, the dynamic interface coupling layer achieves crack closure, sulfide particle rebridging and ion transport pathway restoration through the reversible recombination of the first dynamic bond and the second dynamic interaction. The sulfide solid electrolyte particles serve as a rigid support framework and interfacial bridging fulcrum, limiting crack opening and promoting the redistribution of the self-healing ion-conductive bonding phase at the damaged interface, thereby enhancing the dynamic repair capability of the composite solid electrolyte membrane.

2. The self-healing sulfide composite solid electrolyte membrane according to claim 1, characterized in that, The polymer backbone is composed of structural unit A, structural unit B, structural unit C, and optional structural unit D, and its general formula is: P = Poly[xA + yB + Zc + wD] Wherein, A is a fluorine-containing polar unit, B is a coordination unit, C is a flexible segment unit, and D is a crosslinking unit or branching unit; x, y, z and w are the molar percentages of the corresponding structural units, x is 20% to 94%, y is 1% to 30%, z is 5% to 70%, w is 0% to 20%, and x + y + z + w = ​​100%.

3. The self-healing sulfide composite solid electrolyte membrane according to claim 2, characterized in that, The structural unit A is selected from one or more of the following: fluoroacrylate structural units, fluoromethacrylate structural units, fluorinated vinyl ether structural units, trifluoromethylarylethylene structural units, and fluorinated polyether structural units. The fluoroacrylate structural unit or the fluoromethacrylate structural unit has the following structure: -[CH2-C(R1)(COO-Rf)]- In the formula, R1 is H or CH3, and Rf is a C1 to C10 fluoroalkyl, fluoroalkoxyalkyl, or fluorinated polyether segment. The structural unit B is selected from one or more polymerizable structural units containing imidazole, pyridinyl, triazole or benzimidazole groups.

4. The self-healing sulfide composite solid electrolyte membrane according to claim 2, characterized in that, The structural unit C is selected from one or more of the following: low glass transition temperature acrylate structural units, low glass transition temperature methacrylate structural units, polyether segments, polycarbonate segments, polysiloxane segments, polycaprolactone segments, polybutadiene segments, and polyisoprene segments. The structural unit D is selected from one or more structural units formed from polyethylene glycol diacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate and their derivatives.

5. The self-healing sulfide composite solid electrolyte membrane according to claim 1, characterized in that, The dynamic coordination salt is selected from one or more of Zn(TFSI)2, Zn(OTf)2, Mg(TFSI)2, Mg(OTf)2, Al(OTf)3, Ca(TFSI)2, ZnCl2, CuCl2, MgCl2 and AlCl3; The lithium salt is selected from one or more of LiFSI, LiTFSI, LiDFOB, LiBOB, LiPF6 and LiBF4; The ionic liquid is selected from one or more of imidazolium ionic liquids, pyrrolidineium ionic liquids, piperidinium ionic liquids, and quaternary ammonium salt ionic liquids.

6. The self-healing sulfide composite solid electrolyte membrane according to claim 1, characterized in that, The sulfide solid electrolyte is selected from Li6PS5Cl, Li6PS5Br, Li6PS5I, and Li 7-x PS 6-x Xx, Li3PS4, Li7P3S11, Li 10 GeP2S 12 Li9 .54 Si 1.74 P1 .44 S 11.7 Cl 0.3 One or more of Li2S-P2S5 glass and Li2S-P2S5 glass ceramics, wherein X is Cl, Br or I; The self-healing ion-conductive binder phase accounts for 2 wt% to 12 wt% of the total mass of the composite solid electrolyte membrane; The thickness of the composite solid electrolyte membrane is 10 μm to 200 μm.

7. The self-healing sulfide composite solid electrolyte membrane according to any one of claims 1 to 6, characterized in that, The dynamic interface coupling layer has a continuous or quasi-continuous structure and is distributed on the surface of the sulfide solid electrolyte particles, in the particle contact area, or in the potential crack propagation area. The sulfide solid electrolyte particles and the self-healing ion-conductive bonding phase are combined through one or more interactions such as interfacial adsorption, Lewis acid-base interaction, ion-dipole interaction, electrostatic interaction and mechanical interlocking, so that the first dynamic bond and the second dynamic interaction are preferentially enriched at the particle interface. After the composite solid electrolyte membrane is damaged, the newly exposed sulfide particle surface induces the self-healing ion-conductive binder phase to migrate and rearrange towards the crack tip and particle decontamination area. The confined space between the sulfide particles shortens the cross-crack migration distance of the binder phase, thereby promoting particle reconnection and ion transport pathway reconstruction.

8. A method for preparing a self-healing sulfide composite solid electrolyte membrane according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. A fluorinated polar monomer, a monomer containing a coordinating group, a flexible segment monomer, and an optional crosslinking monomer are polymerized to obtain a polymer backbone containing fluorinated polar units, coordinating units, flexible segment units, and optional crosslinking units or branching units. S2. The polymer skeleton is mixed with a dynamic coordination salt to form a first dynamic bond between the coordination unit and the metal ions in the dynamic coordination salt, and lithium salt and / or ionic liquid are added to prepare a self-healing ion-conductive bonding phase precursor solution. S3. The sulfide solid electrolyte was ball-milled and refined under an inert atmosphere; S4. Mix and disperse the self-healing ion-conductive binder phase precursor liquid with the refined sulfide solid electrolyte to prepare a composite slurry. S5. The composite slurry is coated onto the substrate surface and subjected to one or more of the following processes: drying, demolding, and pressing, to obtain the self-healing sulfide composite solid electrolyte membrane.

9. The preparation method according to claim 8, characterized in that, In step S1, the polymer skeleton is prepared by one or more of the following methods: free radical polymerization, controlled free radical polymerization, ring-opening polymerization, polycondensation, graft polymerization, block polymerization, or interpenetrating network construction. In step S2, the self-healing ion-conductive binder precursor solution is prepared using an anhydrous organic solvent, which is selected from one or more of cyclohexane, toluene, p-xylene, ethyl acetate, isobutyl isobutyrate, acetonitrile, and tetrahydrofuran. In step S3, the ball milling speed is 200-600 rpm, the ball milling time is 7-20 h, and the D50 of the refined sulfide solid electrolyte particles is 0.1-20 μm. In step S5, the drying temperature is 25–120 °C and the pressing pressure is 50–400 MPa.

10. The preparation method according to claim 8 or 9, characterized in that, In step S4, the amount of the self-healing ion-conductive binder precursor solution added, based on the non-volatile components therein, is 2 wt% to 20 wt% of the total mass of the sulfide solid electrolyte and the non-volatile components. The mixing and dispersion is performed by one or more of manual grinding, planetary mixing, shear dispersion and ball milling dispersion, with a mixing time of 10 to 240 min; By controlling the amount of the self-healing ion-conductive binder precursor liquid added, the mixing and dispersion time, and the solvent evaporation rate, the self-healing ion-conductive binder phase is preferentially distributed on the surface of sulfide solid electrolyte particles, particle contact areas, or potential crack propagation areas, forming a continuous or quasi-continuous dynamic interface coupling layer.

11. A fully solid-state lithium battery, characterized in that, It includes a positive electrode layer, a solid electrolyte layer and a negative electrode layer, wherein the solid electrolyte layer includes the self-healing sulfide composite solid electrolyte membrane as described in any one of claims 1 to 7.

12. The all-solid-state lithium battery according to claim 11, characterized in that, The positive electrode active material in the positive electrode layer is selected from one or more of lithium iron phosphate, lithium cobalt oxide, nickel-cobalt-manganese ternary materials, high-nickel ternary materials, lithium-rich manganese-based materials, and sulfur positive electrode materials. The negative electrode layer includes one of lithium metal negative electrode, lithium alloy negative electrode, silicon-based negative electrode, graphite negative electrode, or a current collector without negative electrode.

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