Recyclable sulfide composite solid electrolyte and preparation method therefor

Abstract

Provided in the present disclosure are a recyclable sulfide composite solid electrolyte and a preparation method therefor. The recyclable sulfide composite solid electrolyte comprises: a polymer having a dynamic reversible covalent bond, the polymer integrating the dynamic reversible covalent bond on a main chain or a cross-linked side chain; and a sulfide solid electrolyte.

Description

Recyclable sulfide composite solid electrolyte and preparation method thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure is based on and claims the priority of Chinese patent application with application number 202311799876.2 and application date December 26, 2023. The entire content of the Chinese patent application is hereby incorporated into this disclosure as a reference. Technical Field

[0003] The present disclosure relates to solid electrolytes, and in particular to a recyclable sulfide composite solid electrolyte and a preparation method thereof, a recyclable sulfide composite solid electrolyte membrane, and a solid-state lithium-ion battery comprising the recyclable sulfide composite solid electrolyte membrane. Background Art

[0004] Sulfide solid-state batteries offer excellent chemical stability, a wide temperature range, and good electrical conductivity. To commercialize sulfide solid-state batteries, large-scale film formation of sulfide solid electrolytes is essential. However, sulfide solid electrolytes themselves exhibit poor film-forming properties and require the use of polymer binders to aid film formation. Currently, the optimal solution is to develop organic / inorganic sulfide composite electrolyte membranes.

[0005] Furthermore, considering cost and environmental pressures, battery recycling can significantly reduce carbon emissions throughout its lifecycle, making it an effective measure for controlling carbon emissions within the lithium battery industry chain. Consequently, battery recycling is gaining increasing attention. However, recycling technology for sulfide solid-state batteries is currently lacking. Therefore, the development of recyclable and reusable sulfide solid electrolyte films is of great significance. Summary of the Invention

[0006] In view of the shortcomings of the related art, some objectives of the present disclosure are to provide a recyclable sulfide composite solid electrolyte and a preparation method thereof. The obtained sulfide composite electrolyte can be recycled and has self-repairing ability and an extended service life.

[0007] Another object of the present disclosure is to provide a recyclable sulfide composite solid electrolyte membrane and a solid-state lithium-ion battery comprising the recyclable sulfide composite solid electrolyte membrane.

[0008] In a first aspect, the present disclosure provides a recyclable sulfide composite solid electrolyte, comprising: a polymer having dynamic reversible covalent bonds, wherein the polymer has the dynamic reversible covalent bonds integrated on a main chain or a cross-linked branch; and a sulfide solid electrolyte.

[0009] In some embodiments, the main chain of the polymer having dynamically reversible covalent bonds is a flexible chain, such as one or more of natural rubber, artificial rubber, polyurethane, polyacrylate, polyphosphazene, polyethylene oxide, epoxy resin, polyolefin, polydimethylsilane or polycarbonate.

[0010] In some embodiments, the polymer contains one or more functional groups that can be repeatedly bonded / debonded under light or heat induction, such as anthracene, cinnamate, coumarin, a combination of aldehydes and amines, or a combination of furan and maleimide;

[0011] Optionally, the bonding reaction and debonding reaction of the dynamic reversible covalent bond include at least one of the following reactions:

[0012] i) Bonding and debonding reactions between coumarin molecules:

[0013] ii) Bonding and debonding reactions between substituted or unsubstituted anthracene molecules:

[0014] wherein R is selected from hydrogen; a halogen atom such as fluorine, chlorine, bromine or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom such as fluorine, chlorine, bromine or iodine atom; alternatively, R is selected from hydrogen, methyl, ethyl, n-propyl or n-butyl;

[0015] iii) Bonding and debonding reactions between substituted or unsubstituted furan and substituted or unsubstituted maleimide:

[0016] wherein R1 and R2 are each independently selected from hydrogen; a halogen atom, such as fluorine, chlorine, bromine or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom, such as fluorine, chlorine, bromine or iodine atom; alternatively, R1 and R2 are each independently selected from hydrogen, methyl, ethyl, n-propyl or n-butyl;

[0017] n and m are each an integer greater than or equal to 1, for example, n and m are each an integer in the range of 1 to 1000, for example, an integer in the range of 10 to 500;

[0018] iv) Bonding and debonding reactions between aldehydes and amines:

[0019] wherein R3 and R4 are each independently selected from hydrogen; a halogen atom, such as fluorine, chlorine, bromine or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom, such as fluorine, chlorine, bromine or iodine atom; a cycloalkyl group; an aryl group; a heteroaryl group; alternatively, R3 and R4 are each independently selected from hydrogen, methyl, ethyl, n-propyl or n-butyl;

[0020] v) Bonding and debonding reactions between substituted or unsubstituted cinnamate molecules:

[0021] wherein R5 is selected from hydrogen; a halogen atom such as fluorine, chlorine, bromine or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom such as fluorine, chlorine, bromine or iodine atom; optionally, R5 is selected from hydrogen, methyl, ethyl, n-propyl or n-butyl.

[0022] In some embodiments, the sulfide solid electrolyte is Li2S-P2S5, Li2S-P2S5-MS x 、Li 3.4 Si 0.4 P 0.6 S4, Li 10 GeP2S 11.7 O 0.3 、Li 9.6 P3S 12 、Li7P3S 11 、Li9P3S9O3、Li 10.35 Si 1.35 P 1.65 S 12 、Li 9.81 Sn 0.81 P 2.19 S 12 、Li 10 GeP2S 12 、Li6PS5X、Li7P2S8I、Li 10.35 Ge 1.35 P 1.65 S 12 、Li 3.25 Ge 0.25 P 0.75 S4, Li 10 SnP2S 12 、Li 10 SiP2S12 or Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 wherein M is selected from any one or a combination of at least two of Si, Ge or Sn, X is selected from one or more of Cl, Br or I, and 0≤x≤2.

[0023] In some embodiments, the recyclable sulfide composite solid electrolyte further includes a lithium salt, such as one or more of lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluorophosphate (LiPF6), lithium bis(oxalatoborate) (LiBOB), lithium difluorooxalatoborate (LiDFOB), lithium bis(difluorosulfonyl)imide (LiFSI) or lithium bis(trifluoromethylsulfonyl)imide (LiTFSI); based on the total mass of the recyclable sulfide composite solid electrolyte, the mass fraction of the polymer is 0.2% to 40%, the mass fraction of the sulfide solid electrolyte is 20% to 99.6%, and the mass fraction of the lithium salt is 0.2% to 40%.

[0024] In a second aspect, the present disclosure provides a method for preparing a recyclable sulfide composite solid electrolyte as described in the embodiment of the first aspect of the present disclosure, comprising: mixing a sulfide solid electrolyte and a polymer having a dynamically reversible covalent bond using a slurry method or a dry method to obtain a polymer / sulfide mixture; applying light or heat induction conditions to the polymer / sulfide mixture to obtain the recyclable sulfide composite solid electrolyte.

[0025] In some embodiments, the method further comprises: adding a lithium salt, wherein the lithium salt is mixed with the polymer / sulfide mixture by at least one of screw extrusion, stirring, gas stirring, ball milling, internal mixing, and mixing.

[0026] In some embodiments, the light or heat induction condition includes: irradiation with 360 nm ultraviolet light, or lowering the temperature to below 60°C.

[0027] In a third aspect, the present disclosure provides a recyclable sulfide composite solid electrolyte membrane, comprising the recyclable sulfide composite solid electrolyte described in the embodiment of the first aspect of the present disclosure or the recyclable sulfide composite solid electrolyte prepared by the method described in the embodiment of the second aspect of the present disclosure.

[0028] In a fourth aspect, the present disclosure provides a solid-state lithium-ion battery comprising: a positive electrode; a negative electrode; and a recyclable sulfide composite solid electrolyte membrane according to the embodiment of the third aspect of the present disclosure located between the positive electrode and the negative electrode.

[0029] The recyclable sulfide composite solid electrolyte provided by the embodiment of the present disclosure includes a polymer with a dynamic reversible covalent bond, which integrates the dynamic reversible covalent bond on the main chain or the cross-linked branch; and a sulfide solid electrolyte. In the present disclosure, the recyclable sulfide composite solid electrolyte includes a polymer with a dynamic reversible covalent bond, and the dynamic reversible covalent bond has strong adhesion and ion transport properties. By inducing the dynamic reversible covalent bond to undergo a bonding reaction, the polymer is polymerized or cross-linked, so that the sulfide composite solid electrolyte is bonded into a membrane; by thermochemical or photochemical means, the dynamic reversible covalent bond is debonded, and the polymer is degraded and loses its adhesion, so that the sulfide composite solid electrolyte loses its binder and degrades into powder from the membrane, thereby achieving recycling. Therefore, the sulfide composite electrolyte in the present disclosure can be recycled and has a certain self-repairing ability and an extended service life.

[0030] In the embodiments of the present disclosure, the obtained recyclable sulfide composite solid electrolyte membrane has good flexibility and self-repairing ability, can be applied to flexible lithium-ion batteries, and has high safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0032] FIG1 shows the self-repair process of the recyclable sulfide composite solid electrolyte in an embodiment of the present disclosure.

[0033] FIG2 shows a flow chart of a method for preparing a recyclable sulfide composite solid electrolyte in an embodiment of the present disclosure.

[0034] FIG3 shows a flow chart of a method for preparing a recyclable sulfide composite solid electrolyte membrane in an embodiment of the present disclosure.

[0035] FIG4 shows the ionic conductivity of the initial sulfide powder and the recyclable sulfide composite solid electrolyte membrane prepared according to an embodiment of the present disclosure at different temperatures.

[0036] FIG5 shows X-ray diffraction patterns of initial sulfide powder and a recyclable sulfide composite solid electrolyte membrane according to an embodiment of the present disclosure.

[0037] FIG6 shows a histogram of particle size distribution analysis of Li6PS5Cl using scanning electron microscopy and Nanomeasurements software in an embodiment of the present disclosure.

[0038] FIG7 shows a scanning electron microscope image of a cross section of a recyclable sulfide composite solid electrolyte membrane prepared in an embodiment of the present disclosure.

[0039] FIG8 shows the ionic conductivities of the original membrane and the secondary recovered membrane of the recyclable sulfide composite solid electrolyte membrane prepared according to an embodiment of the present disclosure at different temperature ranges.

[0040] FIG9 shows a CV test graph of a battery prepared according to an embodiment of the present disclosure.

[0041] FIG10 shows a stress-strain curve of a recyclable sulfide composite solid electrolyte membrane prepared according to an embodiment of the present disclosure.

[0042] FIG11 shows a long cycle diagram of a full cell comprising NCM811||sulfide composite solid electrolyte membrane||silicon negative electrode according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, with examples shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims. For those embodiments in which specific conditions are not specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used for which the manufacturer is not specified are conventional products that can be purchased commercially.

[0044] The Chinese patent application number 202010792060.7 provides a separable and recyclable sulfide-based solid electrolyte and its application. Among them, the sulfide-based solid electrolyte is a P-free Sn-based sulfide with the general formula of Li a Sn b A c S d , wherein A is an element doping or replacing Sn, selected from at least one of As, Sb, Bi, Si, W, and Mo, and 0 < a ≤ 4, 0 ≤ b ≤ 1, 0 ≤ c ≤ 0.3, and d = 4. The sulfide-based solid electrolyte is soluble in water and methanol. Since the crystal form remains unchanged after dissolving and heating to evaporate the solvent, the sulfide-based solid electrolyte is recovered.

[0045] Chinese patent application number 202111205105.7 provides a method for preparing a polyethylene oxide solid electrolyte. This method constructs a dynamic boron ester cross-linked PEO network, which is then physically mixed with a lithium salt to form a film. This self-healing, biodegradable, and recyclable dynamic covalently cross-linked PEO solid electrolyte exhibits minimal polarization and excellent stability during cycling.

[0046] Chinese patent application number 201811540502.8 provides a self-healing polymer electrolyte matrix, a preparation method thereof, a self-healing polymer electrolyte, a lithium-ion battery, and its applications. The self-healing polyurethane is obtained via a Diels-Alder reaction, and the reversible action of the furan-maleimide structure in the self-healing polyurethane imparts excellent self-healing capabilities to the matrix.

[0047] However, the recycling of sulfide solid electrolyte membranes has not been reported at this stage. Therefore, the development of recyclable and reusable sulfide solid electrolyte membranes is of great significance.

[0048] As used herein, the term "alkyl group having 1 to 18 carbon atoms" refers to a linear or branched, saturated or unsaturated alkyl group having 1 to 18 carbon atoms. Specific examples of the alkyl group having 1 to 18 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, ethylhexyl, hexyl, heptyl, n-octyl, nonyl, decyl, and dodecyl.

[0049] As used herein, the term "haloalkyl group having 1 to 18 carbon atoms" refers to a linear or branched, saturated or unsaturated haloalkyl group having 1 to 18 carbon atoms, the haloalkyl group containing at least one halogen atom, such as fluorine, chlorine, bromine or iodine atom. Specific examples of haloalkyl groups having 1 to 18 carbon atoms are trifluoromethyl, trichloromethyl, tribromomethyl, difluoroethyl, dichloroethyl, trifluoroethyl, trichloroethyl, tetrafluoroethyl, tetrachloroethyl, pentafluoroethyl, pentachloroethyl, hexafluoroethyl, hexachloroethyl, perfluoroethyl, difluoropropyl, dichloropropyl, trifluoropropyl, trichloropropyl and perfluoropropyl.

[0050] As used herein, the term "cycloalkyl" refers to a cycloalkyl group having 3 to 30 carbon atoms. The cycloalkyl group may be optionally substituted by one or more identical or different groups, for example, these groups are selected from: halogen atoms of fluorine, chlorine, bromine, hydroxyl groups, C1-C 12 Alkyl groups, C1-C 12 Alkoxy groups, C1-C 12 Thioalkoxy groups. Specific examples of cycloalkyl groups are: cyclopropyl, 2,2-difluorocyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, methoxycyclohexyl, fluorocyclohexyl.

[0051] As used herein, the term "aryl" refers to an aromatic carbocyclic group having 6 to 50 carbon atoms. The aryl group may be optionally substituted by one or more identical or different groups, for example, these groups are selected from: halogen atoms of fluorine, chlorine, bromine, hydroxyl groups, C1-C 12 Alkyl groups, C1-C 12 Alkoxy groups, C1-C 12Thioalkoxy groups. Specific examples of aryl groups are: phenyl, methylphenyl, trimethylphenyl, methoxyphenyl, hydroxyphenyl, fluorophenyl, pentafluorophenyl, chlorophenyl, bromophenyl, nitrophenyl, dimethylaminophenyl, naphthyl, phenanthrene, anthracene.

[0052] As used herein, the term "heteroaryl" refers to an aromatic heterocyclic five- or six-atom group having 4 to 50 carbon atoms and 1 to 4 heteroatoms selected from nitrogen, oxygen, sulfur, silicon, and benzo-fused or heterobicyclic rings. The heteroaryl group may be optionally substituted by one or more identical or different groups, for example, these groups are selected from: halogen atoms of fluorine, chlorine, bromine, hydroxyl groups, C1-C 12 Alkyl groups, C1-C 12 Alkoxy groups, C1-C 12 Specific examples of heteroaryl groups are: pyridine, picoline, methoxypyridine, phenylpyridine, fluoropyridine, pyrimidine, pyridazine, pyrazine, quinoline, furan, thiophene, hexylthiophene, bromothiophene, dibromothiophene, pyrrole, oxazole, thiazole, isoxazole, isothiazole, oxadiazole, thiadiazole, pyrazole, imidazole, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, benzoxadiazole, benzothiadiazole, benzopyrazole, benzimidazole.

[0053] An embodiment of the present disclosure provides a recyclable sulfide composite solid electrolyte, comprising: a polymer having dynamic reversible covalent bonds, wherein the dynamic reversible covalent bonds are integrated on the main chain or cross-linked branches of the polymer; and a sulfide solid electrolyte.

[0054] Figure 1 shows the self-repair process of the recyclable sulfide composite solid electrolyte in the embodiment of the present disclosure. Referring to the left part of Figure 1, the dynamic reversible covalent bonds in the polymer are bonded, and the polymer is polymerized or cross-linked, so that the sulfide composite solid electrolyte is bonded together to form a thin film. Referring to the right part of Figure 1, the dynamic reversible covalent bonds in the polymer undergo a debonding reaction, and the polymer degrades and loses its adhesion. Since the sulfide composite solid electrolyte loses the binder, it gradually degrades from a thin film state to a powder state. Therefore, the sulfide composite electrolyte in the present disclosure has self-repairing ability and can be recycled, thereby extending its service life.

[0055] In some embodiments, the main chain of the polymer is a flexible chain, for example, it can be one or more of natural rubber, artificial rubber, polyurethane, polyacrylate, polyphosphazene, polyethylene oxide, epoxy resin, polyolefin, polydimethylsilane or polycarbonate.

[0056] In some embodiments, the polymer contains one or more functional groups that can repeatedly bond / debond under light or heat induction, such as anthracene, cinnamate, coumarin, a combination of aldehyde and amino, a combination of furan and maleimide, and the like.

[0057] In some embodiments, the dynamically reversible covalent bond comprises at least one of a covalent bond between coumarin molecules, a covalent bond between substituted or unsubstituted anthracene molecules, a covalent bond between a substituted or unsubstituted furan and a substituted or unsubstituted maleimide, a covalent bond between aldehydes and amines, and a covalent bond between substituted or unsubstituted cinnamate molecules.

[0058] In some embodiments, the bonding reaction and the debonding reaction of the dynamically reversible covalent bond include at least one of the following reactions (1) to (5).

[0059] (1) The bonding reaction and debonding reaction between coumarin molecules are as follows:

[0060] Coumarin molecules can undergo bonding reactions under the induction of 360nm ultraviolet light and debonding reactions under the induction of 235nm ultraviolet light.

[0061] (2) The bonding reaction and debonding reaction between substituted or unsubstituted anthracene molecules are as follows:

[0062] wherein R is selected from hydrogen; a halogen atom such as fluorine, chlorine, bromine, or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom such as fluorine, chlorine, bromine, or iodine atom. Alternatively, R is selected from hydrogen, methyl, ethyl, n-propyl, or n-butyl. For example, R is selected from hydrogen, methyl, or ethyl. For example, R is hydrogen.

[0063] Alternatively, the reaction formulas for the bonding reaction and debonding reaction between anthracene molecules are as follows:

[0064] Anthracene molecules can undergo bonding reaction under ultraviolet light irradiation conditions, for example, greater than 300nm, optionally 360nm, and undergo debonding reaction under heating conditions, for example, greater than 130°C, optionally 130 to 180°C, for example, 140 to 170°C, for example, 140°C.

[0065] (3) The bonding and debonding reaction between substituted or unsubstituted furan and substituted or unsubstituted maleimide, the reaction formula is as follows:

[0066] Wherein R1 and R2 are each independently selected from hydrogen; a halogen atom such as fluorine, chlorine, bromine or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom such as fluorine, chlorine, bromine or iodine atom. Alternatively, R1 and R2 are each independently selected from hydrogen, methyl, ethyl, n-propyl or n-butyl. Alternatively, R1 and R2 are each independently selected from hydrogen, methyl or ethyl. For example, R1 and R2 are each independently hydrogen.

[0067] Alternatively, the bonding and debonding reaction between furan and maleimide is as follows:

[0068] Wherein n and m are integers greater than or equal to 1, respectively. Optionally, n and m are integers in the range of 1 to 1000, for example, integers in the range of 10 to 500.

[0069] Furan and maleimide can undergo bonding and debonding reactions at different temperatures. For example, bonding occurs at 60°C, while debonding occurs at 120°C.

[0070] (4) The bonding and debonding reaction between aldehydes and amines is as follows:

[0071] Wherein R3 and R4 are each independently selected from hydrogen; a halogen atom such as fluorine, chlorine, bromine or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom such as fluorine, chlorine, bromine or iodine atom. Alternatively, R3 and R4 are each independently selected from hydrogen, methyl, ethyl, n-propyl or n-butyl. For example, R3 and R4 are each independently selected from hydrogen, methyl or ethyl. For example, R3 and R4 are each independently hydrogen.

[0072] Alternatively, the bonding and debonding reactions between aldehydes and amines are as follows:

[0073] For example, the debonding reaction of aldehydes and amines can occur at a temperature above 160° C., such as at a temperature of 170 to 220° C., or at a temperature of 180 to 200° C. The bonding reaction of aldehydes and amines can occur during the cooling process, such as at a temperature in the range of room temperature to 150° C., or at a temperature in the range of room temperature to 80° C. The reaction time and reaction rate vary depending on the nature of the reactants.

[0074] (5) The bonding and debonding reaction between substituted or unsubstituted cinnamate molecules is as follows:

[0075] wherein R5 is selected from hydrogen; a halogen atom such as fluorine, chlorine, bromine or iodine; an alkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms; or a haloalkyl group having 1 to 18, such as 1 to 10, such as 1 to 6, such as 1 to 4 carbon atoms, wherein the haloalkyl group contains at least one halogen atom such as fluorine, chlorine, bromine or iodine atom. Alternatively, R5 is selected from hydrogen, methyl, ethyl, n-propyl or n-butyl. For example, R5 is selected from hydrogen, methyl or ethyl. For example, R5 is hydrogen.

[0076] Alternatively, the reaction formula for the bonding and debonding reaction between cinnamate molecules is as follows:

[0077] Cinnamate molecules can undergo bonding reactions under the induction of 360nm ultraviolet light and debonding reactions under the induction of 235nm ultraviolet light.

[0078] In the bonding and debonding reactions listed above, the induction conditions required for polymer degradation are mild, the film formation after recovery is convenient and rapid, and the recovery method is simple and easy, which is conducive to the large-scale thin-layer production of electrolytes.

[0079] The functional groups involved in the above-mentioned bonding and debonding reactions may exist on the chain segments or on the polymer monomers.

[0080] In some embodiments, the dynamically reversible covalent bond has strong adhesive properties, so that the polymer acts as a binder to assist in film formation of the sulfide composite solid electrolyte.

[0081] In some embodiments, the dynamic reversible covalent bond is used for ion transport. The dynamic reversible covalent bond has a certain ion transport property, which can reduce the internal resistance of the battery composed of the sulfide composite solid electrolyte and further improve the cycle performance of the battery.

[0082] In some embodiments, the sulfide solid electrolyte is LiPSX, wherein X represents one or more of Cl, Br, I; LiGPS; LiSnPS; or LiSiPS. The sulfide solid electrolyte disclosed herein can be prepared according to conventional methods in the art.

[0083] Sulfide solid electrolytes can be glass-ceramic type, sulfide crystalline lithium superion conductor (thio-LISICON) type and argyrodite type. For example, sulfide solid electrolytes can be Li2S-P2S5, Li2S-P2S5-MS x 、Li 3.4 Si 0.4 P 0.6 S4, Li 10 GeP2S 11.7 O 0.3 、Li 9.6 P3S 12 、Li7P3S 11 、Li9P3S9O3、Li 10.35 Si 1.35 P 1.65 S 12 、Li 9.81 Sn 0.81 P 2.19 S 12 、Li 10 GeP2S 12 、Li6PS5X、Li7P2S8I、Li 10.35 Ge 1.35 P 1.65 S 12 、Li 3.25 Ge 0.25 P 0.75 S4, Li 10 SnP2S 12 、Li 10 SiP2S 12 or Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 wherein M is selected from any one or a combination of at least two of Si, Ge or Sn, X is selected from one or more of Cl, Br or I, and 0≤x≤2.

[0084] In some embodiments, the mass fraction of the polymer is 0.2% to 40%, optionally 0.5% to 20%, and for example, 1% to 10%, based on the total mass of the recyclable sulfide composite solid electrolyte. In some embodiments, the mass fraction of the sulfide solid electrolyte is 20% to 99.6%, optionally 60% to 99%, and for example, 80% to 98%, based on the total mass of the recyclable sulfide composite solid electrolyte. In some embodiments, the recyclable sulfide composite solid electrolyte further comprises a lithium salt, and the mass fraction of the lithium salt is 0.2% to 40%, optionally 0.5% to 20%, and for example, 1% to 10%.

[0085] In some embodiments, the lithium salt is selected from one or more inorganic lithium salts or organic lithium salts, such as one or more of lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluorophosphate (LiPF6), lithium bis(oxalatoborate) (LiBOB), lithium difluorooxalatoborate (LiDFOB), lithium bis(difluorosulfonyl imide) (LiFSI), or lithium bis(trifluoromethylsulfonyl imide) (LiTFSI).

[0086] In some embodiments, the recyclable sulfide composite solid electrolyte further includes additives. The additives can be used to improve the physical and chemical properties of the recyclable sulfide composite solid electrolyte. The additives can be organic polymers or inorganic materials. For example, polymer materials can include polyethylene, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylonitrile, polyvinyl alcohol, polyvinylidene chloride, etc.; inorganic materials can include silicon dioxide, titanium dioxide, nickel oxide, silicon oxide, graphene, carbon nanotubes, kaolin, montmorillonite, etc.

[0087] In some embodiments, the recyclable sulfide composite solid electrolyte further comprises a filler, such as a metal atom compound AlO x 、MgO、BiO x etc., oxides or sulfides SiO x 、SiS x , PO x Inorganic particles.

[0088] In the present disclosure, the recyclable sulfide composite solid electrolyte includes a polymer with a dynamic reversible covalent bond, which has strong adhesiveness and ion transport properties. By inducing a bonding reaction of the dynamic reversible covalent bonds, the polymer is polymerized or cross-linked, so that the sulfide composite solid electrolyte is bonded into a membrane; by thermochemical or photochemical methods, the dynamic reversible covalent bonds are debonded, the polymer degrades and loses its adhesiveness, causing the sulfide composite solid electrolyte to lose its binder and degrade into powder from the membrane, thereby achieving recycling. Therefore, the sulfide composite electrolyte in the present disclosure has self-repairing ability and can be recycled, with an extended service life.

[0089] The present disclosure also provides a method for preparing a recyclable sulfide composite solid electrolyte. Referring to FIG2 , the method for preparing a recyclable sulfide composite solid electrolyte in the present disclosure includes the following steps 201 to 202 .

[0090] In step 201 , a sulfide solid electrolyte and a polymer having a dynamically reversible covalent bond are mixed using a slurry method or a dry method to obtain a polymer / sulfide mixture.

[0091] In step 202, light or heat induction conditions are applied to the polymer / sulfide mixture to obtain the recyclable sulfide composite solid electrolyte.

[0092] In some embodiments, before step 201, the above method for preparing a recyclable sulfide composite solid electrolyte further includes: fully grinding the sulfide solid electrolyte to obtain sulfide solid electrolyte particles with an average particle size in the range of 0.3 to 15 μm, optionally 0.5 to 10 μm, for example, 0.5 to 1.5 μm.

[0093] In some embodiments, the mixing method used in step 201 includes screw extrusion, stirring, gas stirring, ball milling, internal mixing, mixing, etc.

[0094] In some embodiments, the method for preparing a recyclable sulfide composite solid electrolyte further comprises: adding a lithium salt, wherein the lithium salt is mixed with the polymer / sulfide mixture using a slurry method or a dry method. The mixing method of the lithium salt and the polymer / sulfide mixture includes screw extrusion, stirring, gas stirring, ball milling, internal mixing, mixing, etc.

[0095] In some embodiments, step 201 may include: dissolving a polymer having a dynamically reversible covalent bond in an organic solvent to obtain a polymer solution, uniformly mixing the polymer solution, a sulfide solid electrolyte, and a lithium salt to obtain a mixed slurry, and drying the mixed slurry to obtain a recyclable sulfide composite solid electrolyte. The drying is performed at a temperature of 60 to 120° C., optionally 75 to 95° C. The organic solvent is one or more of toluene, xylene, hexane, cyclohexane, isobutanol, a halogenated alkane, ethyl acetate, isobutyl isobutyrate, ethylene carbonate, dimethyl carbonate, and acetonitrile.

[0096] In other embodiments, step 201 may include: uniformly mixing a polymer having a dynamically reversible covalent bond, a sulfide solid electrolyte, and a lithium salt to obtain a recyclable sulfide composite solid electrolyte.

[0097] In some embodiments, in step 202, the dynamic reversible covalent bond reaction described above is performed under light- or heat-induced conditions to form a recyclable sulfide composite solid electrolyte. For example, the light- or heat-induced conditions include: irradiation with 360 nm ultraviolet light, or lowering the temperature to below 60° C.

[0098] The embodiments of the present disclosure also provide a recyclable sulfide composite solid electrolyte membrane. The recyclable sulfide composite solid electrolyte membrane is the recyclable sulfide composite solid electrolyte in the above embodiments of the present disclosure or the recyclable sulfide composite solid electrolyte prepared by the method in the above embodiments of the present disclosure.

[0099] In some embodiments, the thickness of the recyclable sulfide composite solid electrolyte membrane is 2-60 μm, optionally 10-50 μm, for example, 20-35 μm.

[0100] In some embodiments, the room temperature ionic conductivity of the recyclable sulfide composite solid electrolyte membrane can be in the range of 0.5 to 6.0 mS·cm -1 The range is 0.7 to 4.5 mS·cm. -1 In the range of, for example, 1.0 to 3.0 mS·cm -1 within the range.

[0101] In some embodiments, the oxidative decomposition voltage of the recyclable sulfide composite solid electrolyte membrane can be 4.0 to 10.0 V (vs Li / Li + ) in the range of 4.5 to 8.5V (vs Li / Li + ) in the range of, for example, 5.0 to 8.0 V (vs Li / Li + ) within the scope of .

[0102] In some embodiments, the tensile strength of the recyclable sulfide composite solid electrolyte membrane is greater than 300 kPa, and may be in the range of 0.4 to 20 MPa, for example, in the range of 0.7 to 10 MPa.

[0103] The present disclosure also provides a method for preparing a recyclable sulfide composite solid electrolyte membrane. Referring to FIG3 , the method for preparing a recyclable sulfide composite solid electrolyte membrane includes the following steps 301 to 302 .

[0104] In step 301 , a sulfide solid electrolyte and a polymer having a dynamically reversible covalent bond are mixed using a slurry method or a dry method to obtain a polymer / sulfide mixture.

[0105] In step 302, light or heat induction conditions are applied to the polymer / sulfide mixture to obtain the recyclable sulfide composite solid electrolyte.

[0106] The operation processes of step 301 and step 302 are respectively the same as the operation processes of step 201 and step 202 described above, and are not repeated here.

[0107] In step 303, the recyclable sulfide composite solid electrolyte is subjected to a film-forming treatment to obtain a recyclable sulfide composite solid electrolyte membrane.

[0108] In some embodiments, step 303 may include: uniformly coating the mixed slurry on the substrate and performing a drying process to obtain a sulfide composite solid electrolyte uniformly distributed on the surface of the substrate; and peeling the uniformly distributed sulfide composite solid electrolyte from the substrate to obtain a recyclable sulfide composite solid electrolyte membrane.

[0109] In other embodiments, step 303 may include: rolling the polymer having a dynamically reversible covalent bond, the sulfide solid electrolyte, and the lithium salt to obtain a sulfide composite solid electrolyte uniformly distributed on the surface of the substrate; and peeling the uniformly distributed sulfide composite solid electrolyte from the substrate to obtain a recyclable sulfide composite solid electrolyte membrane.

[0110] In some embodiments, the thickness of the recyclable sulfide composite solid electrolyte membrane is 2-60 μm, optionally 10-50 μm, for example, 20-35 μm.

[0111] During the film-forming process, the polymer undergoes polymerization or cross-linking reactions, resulting in the formation of a thin film of the sulfide composite solid electrolyte. This process utilizes traditional slurry methods or solvent-free or low-solvent in-situ solidification methods, making it applicable to a variety of technical routes and enabling rapid industrialization with cost and environmental advantages.

[0112] In some embodiments, the substrate may be a polyethylene terephthalate film. In the present disclosure, the substrate may be selected according to actual needs, as long as it can provide a certain support effect so that the mixed slurry can form a film on the substrate.

[0113] In the embodiments of the present disclosure, the obtained recyclable sulfide composite solid electrolyte membrane has good flexibility and self-repairing ability, can be applied to flexible lithium-ion batteries, and has high safety and reliability.

[0114] According to the method disclosed in the embodiment of the present invention, a recyclable sulfide composite solid electrolyte is prepared. Since a polymer with dynamically reversible covalent bonds is used as an adhesive material and directly mixed with the sulfide solid electrolyte, a self-repairable sulfide composite solid electrolyte film is obtained. This simplifies the preparation process of the recyclable sulfide composite solid electrolyte film, is easy to operate, has a high yield, and can achieve large-scale thinning of the electrolyte (<20μm), which is beneficial to improving energy density and safety.

[0115] The present disclosure provides a battery, which may be a solid-state lithium-ion battery, comprising a recyclable sulfide composite solid electrolyte according to an embodiment of the present disclosure. The recyclable sulfide composite solid electrolyte is located between the positive electrode and the negative electrode of the battery.

[0116] The positive and negative electrodes of the battery can be selected based on actual needs. For example, the active material of the positive electrode includes at least one of lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, lithium vanadium phosphate, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide; the active material of the negative electrode includes at least one of silicon, metallic lithium, graphite, mesophase carbon fiber, mesophase carbon microbeads, soft carbon, hard carbon, and a silicon-carbon composite material.

[0117] The battery provided by the present disclosure can be a single-chip all-solid-state battery, which is obtained by directly stacking and assembling a recyclable sulfide composite solid electrolyte membrane and the positive and negative electrode sheets of a lithium-ion battery.

[0118] The battery provided by the present disclosure can also be a bipolar all-solid-state battery, which is obtained by directly stacking and assembling a recyclable sulfide composite solid electrolyte membrane and the positive and negative electrode sheets of a lithium-ion battery.

[0119] The recyclable sulfide composite solid electrolyte membrane obtained in the present disclosure has high flexibility and ionic conductivity, can be adapted to various electrode materials, and can be adapted to the existing lamination process, and has the prospect of rapid industrialization.

[0120] Example 1: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 1

[0121] 980 mg of sulfide solid electrolyte Li6PS5Cl was thoroughly ground in a ball mill to obtain particles with an average particle size of 1 μm. 10 mg of vinyl coumarin was weighed. The above sulfide solid electrolyte particles and coumarin were mixed and placed in a film-forming mold. After casting into a film, the film was heated and polymerized. After curing, a sulfide composite solid electrolyte was obtained. The mold was cooled to room temperature and irradiated with 360 nm ultraviolet light until the composite electrolyte could be completely demolded. A recyclable sulfide composite solid electrolyte membrane was obtained.

[0122] Figure 4 shows the ionic conductivity of the initial sulfide powder and the recyclable sulfide composite solid electrolyte membrane prepared according to an embodiment of the present disclosure at different temperatures. As shown in Figure 4, at the same temperature, the ionic conductivity of the recyclable sulfide composite solid electrolyte membrane prepared according to an embodiment of the present disclosure is higher than that of the initial sulfide powder.

[0123] FIG5 shows X-ray diffraction patterns of initial sulfide powder and a recyclable sulfide composite solid electrolyte membrane according to an embodiment of the present disclosure.

[0124] Example 2: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 2

[0125] Weigh 100g of coumarin dipropanol, use toluene as solvent, mix it with toluene diisocyanate in a molar ratio of 1:1.1, use dibutyltin dilaurate as initiator, and polymerize at 60℃ to obtain a polyurethane with coumarin side groups.11 Grind thoroughly with a ball mill to obtain particles with an average particle size of 1 μm. Take 10 mg of coumarin side group substituted polyurethane and dissolve it in 50 mL of toluene and stir until it is completely dissolved. Mix the above-mentioned sulfide solid electrolyte particles, polyurethane with coumarin side groups, and toluene solution, and stir thoroughly until uniform to obtain a mixed solution. Pour the mixed solution into a mold and dry it at 80°C for 6 hours. Irradiate the dried mold under 360 nm ultraviolet light until the composite electrolyte can be completely demolded to obtain a recyclable sulfide composite solid electrolyte membrane.

[0126] Example 3: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 3

[0127] 980 mg of sulfide solid electrolyte Li6PS5Cl was fully ground in a ball mill to obtain particles with an average particle size of 1 μm. 10 mg of butenyl anthracene was weighed. Using toluene as a solvent, the above-mentioned sulfide solid electrolyte particles and butenyl anthracene were evenly mixed and placed in a film-forming mold. After cast film formation, the film was heated and polymerized, and in-situ cured to obtain a sulfide composite solid electrolyte. The mold cooled to room temperature was irradiated under 300 nm ultraviolet light until the composite electrolyte could be completely demolded, thereby obtaining a recyclable sulfide composite solid electrolyte membrane.

[0128] Example 4: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 4

[0129] Weigh 100g of hexenyl anthracene, use toluene as solvent and azobisisobutyronitrile as initiator, and perform free radical polymerization at 60℃ to obtain a hexene polymer with anthracene side groups. 11 Grind thoroughly with a ball mill to obtain particles with an average particle size of 1 μm. Take 10 mg of the above-obtained polymer and dissolve it in 50 mL of ethyl acetate and stir until it is completely dissolved. Mix the above-mentioned sulfide solid electrolyte particles, anthracene side-group hexene polymer, and ethyl acetate solution, and stir thoroughly until uniform to obtain a mixed solution. Pour the mixed solution into a mold and dry it at 80°C for 6 hours. Irradiate the dried mold under 360 nm ultraviolet light until the composite electrolyte can be completely demolded to obtain a recyclable sulfide composite solid electrolyte membrane.

[0130] Example 5: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 5

[0131] 980mg of sulfide solid electrolyte Li6PS5Cl was thoroughly ground in a ball mill to obtain particles with an average particle size of 1μm. 10mg of vinyl furan and ethylene maleimide were weighed in a 1:1 molar ratio. Using petroleum ether as a solvent, the sulfide solid electrolyte particles, vinyl furan, and ethylene maleimide were evenly mixed. The mixture was placed in a film-forming mold and, after cast film formation, heated at 60°C for polymerization and cross-linking reactions until the composite electrolyte could be completely demolded, resulting in a recyclable sulfide composite solid electrolyte membrane.

[0132] Example 6: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 6

[0133] 10g of diaminoethyl furan and epoxidized soybean oil maleimide were weighed in a molar ratio of 1:1, and tetrahydrofuran was used as solvent. The mixture was stirred and polymerized at room temperature to obtain an epoxy resin with furan and maleimide side groups. 980mg of sulfide solid electrolyte Li7P3S 11 Grind thoroughly with a ball mill to obtain particles with an average particle size of 1 μm. Take 10 mg of the epoxy resin obtained above and dissolve it in 50 mL of toluene and stir until it is completely dissolved. Mix the above-mentioned sulfide solid electrolyte particles, epoxy resin with furan and maleimide side groups, and toluene solution, and stir thoroughly until uniform to obtain a mixed solution. Pour the mixed solution into a mold and dry it at 60°C for 6 hours. Until the composite electrolyte can be completely demolded, a recyclable sulfide composite solid electrolyte membrane can be obtained.

[0134] Example 7: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 7

[0135] 980mg of sulfide solid electrolyte Li6PS5Cl was fully ground in a ball mill to obtain particles with an average particle size of 1μm. 10mg of diethylamine and glutaraldehyde were weighed in a molar ratio of 1:1. Using tetrahydrofuran as a solvent, the above sulfide solid electrolyte particles, diethylamine and glutaraldehyde were evenly mixed and placed in a film-forming mold. After casting the film, it was heated and polymerized at the same time. Then it was heated to 160℃ and kept warm for 2 hours until the composite electrolyte could be completely demolded. The recyclable sulfide composite solid electrolyte membrane was obtained.

[0136] Example 8: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 8

[0137] Weigh 10g of allyl aldehyde, use tetrahydrofuran as solvent, azobisisobutyronitrile as initiator, stir and polymerize at 60℃ to obtain an alkane with aldehyde side groups. 11Grind thoroughly with a ball mill to obtain particles with an average particle size of 1 μm. Take 5 mg of the above-obtained aldehyde side-group alkane and 5 mg of chitosan and dissolve them in 50 mL of ethyl acetate and stir until they are completely dissolved. Mix the above-mentioned sulfide solid electrolyte particles, aldehyde side-group alkane, chitosan and ethyl acetate solution, and stir thoroughly until uniform to obtain a mixed solution. Pour the mixed solution into a mold and dry it at 50°C. Heat it to 160°C and keep it warm for at least 2 hours until the composite electrolyte can be completely demolded to obtain a recyclable sulfide composite solid electrolyte membrane.

[0138] Example 9: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 9

[0139] 980 mg of sulfide solid electrolyte Li6PS5Cl was thoroughly ground in a ball mill to obtain particles with an average particle size of 1 μm. 10 mg of hexenyl cinnamate was weighed and placed in a film-forming mold using tetrahydrofuran as a solvent. After casting, the film was simultaneously heated and polymerized. The film was then irradiated with 360 nm ultraviolet light until the composite electrolyte could be completely demolded, resulting in a recyclable sulfide composite solid electrolyte membrane.

[0140] Example 10: Preparation of Recyclable Sulfide Composite Solid Electrolyte Membrane 10

[0141] Weigh 10g of hexenyl cinnamate, use tetrahydrofuran as solvent, azobisisobutyronitrile as initiator, stir and polymerize at 60℃ to obtain polyhexene with cinnamate side groups. 11 Grind thoroughly with a ball mill to obtain particles with an average particle size of 1 μm. Take 5 mg of the above-obtained polyhexene with cinnamate side groups, dissolve it in 50 mL of ethyl acetate, and stir until it is completely dissolved. Mix the above-mentioned sulfide solid electrolyte particles, polyhexene with cinnamate side groups, and ethyl acetate solution, and stir thoroughly until uniform to obtain a mixed solution. Pour the mixed solution into a mold and dry it at 50°C. Then irradiate under 360 nm ultraviolet light until the composite electrolyte can be completely demolded to obtain a recyclable sulfide composite solid electrolyte membrane.

[0142] Performance Testing

[0143] The following describes the testing methods for the performance parameters involved in the embodiments of the present disclosure.

[0144] 1. Average particle size

[0145] The particle size distribution of sulfide solid electrolytes was analyzed using scanning electron microscopy and Nanomeasurements software. For example, the scanning electron micrographs of Li6PS5Cl are shown in Figures 6(a) and 6(b). Analysis using Nanomeasurements software, as shown in Figure 6(c), shows that the particle size distribution is primarily between 0.5 and 1.5 μm, accounting for 86.7%, with a D50 of ≈ 0.77 μm.

[0146] 2. Thickness

[0147] The thickness of the recyclable sulfide composite solid electrolyte membrane obtained in the examples of the present disclosure was measured by scanning electron microscopy of the membrane cross-section. For example, a scanning electron micrograph of the recyclable sulfide composite solid electrolyte membrane obtained in Example 1 is shown in Figure 7. The recyclable sulfide composite solid electrolyte membrane has a uniform thickness of approximately 30 μm. The energy spectrum further characterizes the distribution of polymer and sulfide within the membrane, where oxygen originates from the polymer, and phosphorus and sulfur originate from the sulfide solid electrolyte, exhibiting very high uniformity.

[0148] 3. Ionic conductivity at different temperature ranges

[0149] The electrochemical impedance spectroscopy (EIS) instrument was used for measurement. The recyclable sulfide composite solid electrolyte membrane was assembled into a steel-to-steel symmetrical cell, and frequency scanning was performed to measure the room temperature ionic conductivity.

[0150] First, the prepared recyclable sulfide composite solid electrolyte membrane was assembled into a steel-to-steel symmetrical cell, and a frequency sweep was performed to measure the ionic conductivity. The AC impedance spectrum in the frequency range of 100 MHz to 7 MHz was tested with a 10 mV perturbation, and the corresponding impedance value was read. The ionic conductivity can be calculated according to the formula σ = L / RS, where L is the thickness of the recyclable sulfide composite solid electrolyte membrane in cm; R is the impedance of the recyclable sulfide composite solid electrolyte membrane in Ω; and S is the area of ​​the recyclable sulfide composite solid electrolyte membrane in cm. 2 . The binder in the electrolyte membrane is then degraded, shredded and re-formed into a membrane to simulate the recycling of sulfide solid electrolyte membranes in actual scenarios. The secondary recycled sulfide solid electrolyte membrane is then assembled into a steel-to-steel symmetrical cell, and a frequency sweep is performed to measure the ionic conductivity. The measurement range is 30 to 80°C, and the test is performed every 10°C increase in temperature. For example, according to the test of the recyclable sulfide composite solid electrolyte membrane in Example 1, the results are shown in Figure 8.

[0151] 4. Oxidation decomposition voltage

[0152] CV testing was performed on a battery composed of stainless steel || recyclable sulfide composite solid electrolyte membrane || lithium metal to characterize its electrochemical stability. Linear sweep voltammetry (LSV) testing of the recyclable sulfide composite solid electrolyte membrane was performed using a multi-channel electrochemical workstation (VMP-300). The relationship between current and voltage was measured over a voltage range of 0 to 5.0 V at a sweep rate of 1 mV / s. The voltage at which the sulfide composite solid electrolyte membrane began to oxidize and decompose was determined by analyzing the current-voltage curve.

[0153] Figure 9 shows the CV test curve of a full cell prepared using the recyclable sulfide composite solid electrolyte membrane in Example 1. Analysis shows that the recyclable sulfide composite solid electrolyte membrane obtained in Example 1 has a response current of less than 0.2 μA at a high voltage of 5 V, demonstrating a very high electrochemical window.

[0154] 5. Tensile strength

[0155] The sulfide solid electrolyte membrane was formed into a uniform film 70 mm long, 10 mm wide, and 0.1 mm thick. The film was then placed in the fixture of a universal testing machine (MTS E43.104). A tensile force was applied to both ends of the specimen using a universal tensile testing machine to obtain stress-strain curves and evaluate the tensile properties of the sulfide solid electrolyte membrane. Measurements were taken of the recyclable sulfide composite solid electrolyte membrane in Example 1, both in its initial state and after recycling. The results are shown in Figure 10 below.

[0156] As shown in Figure 10, although the mechanical strength of the membrane is reduced after secondary processing, it can still maintain a tensile strength of >300kPa, which meets the requirements of stacking in modern battery production and has the potential to assemble batteries again.

[0157] The physical and chemical properties of the recyclable sulfide composite solid electrolyte membranes of Examples 1-10 were tested, and the results are shown in Table 1.

[0158] Table 1. Chemical composition and physicochemical properties of the recyclable sulfide composite solid electrolyte membranes of Examples 1-10

[0159] Preparation of full batteries

[0160] LiNiCoMnO4 (NCM811) was used as the positive electrode material of the battery, and silicon was used as the negative electrode material. The recyclable sulfide composite solid electrolyte membrane laminate obtained in Example 1 of the present disclosure was assembled into an NCM811||sulfide composite solid electrolyte membrane||silicon negative electrode full battery. The long cycle diagram of the obtained full battery is shown in Figure 11 (a). As shown in Figure 11 (a), at a rate of 0.2C, 2.7-4.2V (vs. Li + The charge and discharge tests were carried out within a voltage range of 1 / Li, and the capacity retention rate of the full battery using the above-mentioned NCM811||sulfide composite solid electrolyte membrane||silicon negative electrode after 100 cycles was 99%.

[0161] The sulfide composite solid electrolyte membrane obtained in Example 1 of the present disclosure was recycled to obtain a recycled sulfide composite solid electrolyte membrane. The recycled sulfide composite solid electrolyte membrane was assembled into an NCM811||recycled sulfide composite solid electrolyte membrane||silicon negative electrode full cell according to the above steps. The long cycle diagram of the obtained full cell is shown in Figure 11(b). As shown in Figure 11(b), at a rate of 0.2C, 2.7-4.3V (vs.Li + The charge and discharge tests were carried out within a voltage range of 1 / Li, and the capacity retention rate of the full battery using the above-mentioned NCM811||sulfide composite solid electrolyte membrane||silicon negative electrode after 100 cycles was 99%.

[0162] The recyclable sulfide composite solid electrolyte membrane provided by the embodiments of the present disclosure can be recycled, has a certain degree of self-repairing ability, and can be applied to full batteries, thereby achieving battery recycling and reducing battery carbon emissions.

[0163] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

[0164] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A recyclable sulfide composite solid electrolyte, the recyclable sulfide composite solid electrolyte comprising: A polymer having dynamic reversible covalent bonds, the polymer integrating the dynamic reversible covalent bonds on the main chain or crosslinked side chains; A sulfide solid electrolyte.

2. The recyclable sulfide composite solid electrolyte according to claim 1, wherein, The main chain of the polymer having dynamic reversible covalent bonds is a flexible chain.

3. The recyclable sulfide composite solid electrolyte according to claim 2, wherein, The main chain of the polymer having dynamic reversible covalent bonds is one or more of natural rubber, synthetic rubber, polyurethane, polyacrylate, polyphosphazene, polyethylene oxide, epoxy resin, polyolefin, polydimethylsilane or polycarbonate.

4. The recyclable sulfide composite solid electrolyte according to any one of claims 1 to 3, wherein The polymer contains one or more functional groups that can be repeatedly bonded / debonded under light or heat induction.

5. The recyclable sulfide composite solid electrolyte according to claim 4, wherein, The bonding reaction and debonding reaction of the dynamic reversible covalent bonds include at least one of the following reactions: i) Bonding reaction and debonding reaction between coumarin molecules: ii) Bonding and debonding reactions between substituted or unsubstituted anthracene molecules: wherein R is selected from hydrogen; a halogen atom; an alkyl group having 1 to 18 carbon atoms; or a halogenated alkyl group having 1 to 18 carbon atoms, wherein the halogenated alkyl group contains at least one halogen atom; iii) Bonding and debonding reactions between substituted or unsubstituted furans and substituted or unsubstituted maleimides: wherein R1 and R2 are each independently selected from hydrogen; a halogen atom; an alkyl group having 1 to 18 carbon atoms; or a halogenated alkyl group having 1 to 18 carbon atoms, wherein the halogenated alkyl group contains at least one halogen atom; n and m are each an integer greater than or equal to 1; iv) Bonding and debonding reactions between aldehydes and amines: wherein R3 and R4 are each independently selected from hydrogen; a halogen atom; an alkyl group having 1 to 18 carbon atoms; or a halogenated alkyl group having 1 to 18 carbon atoms, wherein the halogenated alkyl group contains at least one halogen atom; a cycloalkyl group; an aryl group; a heteroaryl group; v) Bonding and debonding reactions between substituted or unsubstituted cinnamate molecules: wherein R5 is selected from hydrogen; a halogen atom; an alkyl group having 1 to 18 carbon atoms; or a halogenated alkyl group having 1 to 18 carbon atoms, wherein the halogenated alkyl group contains at least one halogen atom.

6. The recyclable sulfide composite solid electrolyte according to claim 5, wherein, The halogen atom is selected from fluorine, chlorine, bromine or iodine; R is selected from hydrogen, methyl, ethyl, n-propyl or n-butyl; R1 and R2 are each independently selected from hydrogen, methyl, ethyl, n-propyl or n-butyl; R3 and R4 are each independently selected from hydrogen, methyl, ethyl, n-propyl or n-butyl; R5 is selected from hydrogen, methyl, ethyl, n-propyl or n-butyl.

7. The recyclable sulfide composite solid electrolyte according to any one of claims 1 to 3, wherein The sulfide solid electrolyte is one or more of Li2S-P2S5, Li2S-P2S5-MS x , Li 3.4 Si 0.4 P 0.6 S4, Li 10 GeP2S 11.7 O 0.3 , Li 9.6 P3S 12 , Li7P3S 11 , Li9P3S9O3, Li 10.35 Si 1.35 P 1.65 S 12 , Li 9.81 Sn 0.81 P 2.19 S 12 , Li 10 GeP2S 12 , Li6PS5X, Li7P2S8I, Li 10.35 Ge 1.35 P 1.65 S 12 , Li 3.25 Ge 0.25 P 0.75 S4, Li 10 SnP2S 12 , Li 10 SiP2S 12 or Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 ; wherein, M is selected from any one or a combination of at least two of Si, Ge or Sn; X is selected from one or more of Cl, Br or I; and 0 ≤ x ≤ 2.

8. The recyclable sulfide composite solid electrolyte according to any one of claims 1 to 3, wherein, The recyclable sulfide composite solid electrolyte further comprises a lithium salt; Based on the total mass of the recyclable sulfide composite solid electrolyte, the mass fraction of the polymer is 0.2% to 40%, the mass fraction of the sulfide solid electrolyte is 20% to 99.6%, and the mass fraction of the lithium salt is 0.2% to 40%.

9. The recyclable sulfide composite solid electrolyte according to claim 8, wherein, The lithium salt is selected from one or more of lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium hexafluoroarsenate (LiAsF6), lithium hexafluorophosphate (LiPF6), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium bis(difluoromethanesulfonyl)imide (LiFSI) or lithium bis(trifluoromethylsulfonyl)imide (LiTFSI).

10. A method for preparing the recyclable sulfide composite solid electrolyte according to any one of claims 1 to 9, comprising: Mixing a sulfide solid electrolyte and a polymer having dynamic reversible covalent bonds by a slurry method or a dry method to obtain a polymer / sulfide mixture; Applying light or heat induction conditions to the polymer / sulfide mixture to obtain the recyclable sulfide composite solid electrolyte.

11. The method according to claim 10, wherein, The method further includes: Adding a lithium salt, wherein the lithium salt is mixed with the polymer / sulfide mixture by at least one of screw extrusion, stirring, gas stirring, ball milling, internal mixing, and kneading.

12. The method according to claim 10 or 11, wherein The light or heat induction conditions include: ultraviolet light irradiation at 360 nm, or reducing the temperature to below 60 °C.

13. A recyclable sulfide composite solid electrolyte membrane, comprising the recyclable sulfide composite solid electrolyte according to any one of claims 1 to 9 or the recyclable sulfide composite solid electrolyte prepared by the method according to any one of claims 10 to 12.

14. A solid-state lithium-ion battery, comprising: A positive electrode; A negative electrode; And The recyclable sulfide composite solid electrolyte membrane according to claim 13 located between the positive electrode and the negative electrode.

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