Quasi-solid-state electrolyte, method for producing the same, and battery

Abstract

The application provides a quasi-solid-state electrolyte and a preparation method and a battery thereof, and relates to the field of solid-state electrolytes. The quasi-solid-state electrolyte comprises an electrolyte, para-aramid nanofibers and an amorphous metal-organic framework; wherein the amorphous metal-organic framework is located on the surface of the para-aramid nanofibers. The para-aramid nanofibers and the amorphous metal-organic framework have good interfacial compatibility, which helps to improve the lithium ion conductivity and cycle stability of the quasi-solid-state electrolyte.

Description

Technical Field

[0001] This invention relates to the field of solid-state electrolyte technology, specifically to a quasi-solid-state electrolyte, its preparation method, and a battery. Background Technology

[0002] Lithium-ion batteries are characterized by high energy density, long cycle life, and environmental friendliness, and are widely used in new energy vehicles and energy storage systems. Traditional lithium-ion batteries often use liquid electrolytes to transport lithium ions. However, dendrites easily form at the interface between the negative electrode and the liquid electrolyte. Dendrites can not only easily pierce the separator and cause internal short circuits, but also lead to thermal runaway, which seriously limits the application and industrialization of lithium-ion batteries.

[0003] In existing technologies, some research teams have replaced liquid electrolytes with quasi-solid-state electrolytes containing inorganic fillers to address the aforementioned problems. Polymers help suppress dendrite formation, while inorganic fillers improve ion conduction efficiency. However, poor interfacial compatibility between inorganic fillers and polymers prevents the inorganic fillers from fully utilizing their conductivity advantages, resulting in low lithium-ion conductivity and poor cycle stability in the quasi-solid-state electrolyte, significantly limiting its application potential. Summary of the Invention

[0004] In view of the technical problems existing in the background art, this application provides a quasi-solid electrolyte, its preparation method and battery, aiming to solve the technical problem that the poor interfacial compatibility between inorganic fillers and polymers in quasi-solid electrolytes leads to low lithium-ion conductivity and poor cycle stability.

[0005] In a first aspect, embodiments of this application provide a quasi-solid electrolyte, including an electrolyte, para-aramid nanofibers, and an amorphous metal-organic framework (amorphous MOF); wherein the amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

[0006] In the technical solution of this application embodiment, an amorphous metal-organic framework is used as a filler and para-aramid nanofibers are used as a polymer skeleton to obtain a quasi-solid electrolyte. The amorphous metal-organic framework has a long-range disordered structure, which gives it the following technical effects: (1) it makes the interfacial contact between the amorphous metal-organic framework and the para-aramid nanofibers closer; (2) the amorphous metal-organic framework has high surface activity, which can promote the formation of strong chemical bonds between the two phases; (3) it gives the amorphous metal-organic framework good flexibility and structural adaptability, which can more uniformly disperse and transfer stress. The aforementioned technical effects promote the interfacial coupling between the amorphous metal-organic framework and the para-aramid nanofibers and significantly improve their interfacial compatibility, thereby improving the lithium-ion conductivity and cycle stability of the quasi-solid electrolyte.

[0007] In some embodiments, the mass ratio of electrolyte, para-aramid nanofibers, and amorphous metal-organic framework is 1:(2.7~30.0):(12.2~69.0).

[0008] In this embodiment, the above-mentioned mass ratio range helps to form a stable electrolyte framework and good ion transport channels, thereby simultaneously improving the cycle stability and lithium-ion conductivity of the quasi-solid electrolyte.

[0009] In some embodiments, the electrolyte includes at least one of lithium-sulfur electrolyte, lithium-ion secondary electrolyte, and ionic liquid, and the electrolyte contains lithium salt.

[0010] In this embodiment, the type of electrolyte described above is beneficial to improving the transport efficiency of lithium ions in the quasi-solid electrolyte, thereby further improving the lithium ion conductivity.

[0011] In some embodiments, the metal element in the amorphous metal-organic framework includes at least one of nickel and iron.

[0012] In this embodiment, the amorphous metal-organic framework containing the aforementioned metal elements has good ionic conductivity, which can effectively improve the lithium-ion transport performance of the quasi-solid electrolyte.

[0013] Secondly, embodiments of this application provide a method for preparing a quasi-solid-state electrolyte, comprising the following steps:

[0014] The ligand and the first solvent phase are mixed to obtain a ligand solution;

[0015] Para-aramid fibers, an alkali agent, and a second solvent are mixed to obtain a first mixture. Subsequently, the first mixture is mixed with a protic solvent to obtain a second mixture.

[0016] The second mixture is subjected to a first solid-liquid separation and solvent replacement treatment to obtain an aramid nanofiber dispersion containing para-aramid nanofibers.

[0017] A third mixture was obtained by mixing an aramid nanofiber dispersion, a metal salt, and a ligand solution.

[0018] The third mixture is subjected to a second solid-liquid separation to obtain the first membrane layer. Subsequently, the first membrane layer is wetted with electrolyte and dried to obtain a quasi-solid electrolyte.

[0019] The quasi-solid electrolyte includes an electrolyte, para-aramid nanofibers, and an amorphous metal-organic framework; the amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

[0020] In the technical solution of this application embodiment, the above preparation method first uses an alkali agent to fully deprotonate the para-aramid fibers, which helps to promote the swelling, exfoliation, and refinement of the para-aramid fibers to obtain para-aramid nanofibers. Then, a protonated solvent is used to fully protonate and exfoliate the para-aramid nanofibers to promote uniform fiber dispersion. After a first solid-liquid separation and solvent replacement treatment, an aramid nanofiber dispersion is obtained. By mixing and reacting the aramid nanofiber dispersion, metal salt, and ligand solution, it is helpful to grow amorphous metal-organic framework in situ on the surface of para-aramid nanofibers, while promoting the uniform distribution of amorphous metal-organic frameworks on the surface of para-aramid nanofibers, thereby effectively improving the interfacial compatibility and coupling strength of the two, and thus improving the lithium-ion conductivity and cycle stability of the quasi-solid electrolyte.

[0021] In some embodiments, the ligand comprises at least one of terephthalic acid, phenylphosphonic acid, and 2-aminoterephthalic acid.

[0022] In this embodiment, the ligand can react with metal ions to generate an amorphous metal-organic framework in situ on the surface of para-aramid nanofibers, thereby improving the lithium-ion transport performance of the quasi-solid electrolyte.

[0023] In some embodiments, the alkali agent comprises at least one of potassium hydroxide, sodium hydroxide, potassium tert-butoxide, and sodium tert-butoxide.

[0024] In this embodiment, the aforementioned alkaline agent facilitates deprotonation, promoting swelling, exfoliation, and refinement of the para-aramid fibers to obtain para-aramid nanofibers, which are then uniformly dispersed in a solvent. The preparation of uniformly dispersed para-aramid nanofibers is beneficial for the uniform growth of amorphous metal-organic frameworks, thereby enhancing the lithium-ion transport performance of the quasi-solid-state electrolyte.

[0025] In some embodiments, the metal salt comprises at least one of nickel acetate tetrahydrate, ferric chloride hexahydrate, and ferrous chloride tetrahydrate.

[0026] In this embodiment, limiting the types of metal salts to the above-mentioned range helps to limit the types of metals, thereby ensuring the preparation of an amorphous metal-organic framework. On the other hand, the metal cations obtained after dissolving the metal salts can be uniformly adsorbed on the surface of para-aramid nanofibers, promoting the uniform distribution of the amorphous metal-organic framework on the surface of para-aramid nanofibers, thereby improving the lithium-ion transport performance of the quasi-solid electrolyte.

[0027] In some embodiments, the mass ratio of para-aramid nanofibers, ligands, and metal salts is 1:(3.0~9.3):(2.7~15.9).

[0028] In this embodiment, the above-mentioned mass ratio range helps to promote the uniform and sufficient loading of amorphous metal-organic frameworks on the surface of para-aramid nanofibers, thereby improving the lithium-ion transport performance of the quasi-solid electrolyte.

[0029] In some embodiments, the mass ratio of para-aramid fiber to alkali agent is 1:(1.2~1.8).

[0030] In this embodiment, by controlling the amount of alkali agent within the aforementioned range, it is beneficial to fully deprotonate the para-aramid fibers, thereby promoting their exfoliation and obtaining para-aramid nanofibers. This provides sufficient active sites for the in-situ growth of amorphous metal-organic frameworks, promotes the interfacial bonding between the amorphous metal-organic framework and the para-aramid nanofibers, and thus improves interfacial compatibility. Furthermore, rationally controlling the amount of alkali agent also helps to control the size of the para-aramid nanofibers within a suitable range, giving them good mechanical properties, thereby enabling the quasi-solid electrolyte to have good mechanical strength.

[0031] In some embodiments, the first solvent comprises at least one of N,N-dimethylformamide (DMF), acetonitrile, and ethanol.

[0032] In this embodiment, the solvent can regulate the rate of coordination reaction, promote the uniform and stable growth of amorphous metal-organic frameworks on the surface of para-aramid nanofibers, thereby improving the lithium-ion transport performance and cycle performance of the quasi-solid electrolyte.

[0033] In some embodiments, the second solvent comprises at least one of dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0034] In this embodiment, the solvent is a strongly polar aprotic solvent, which can fully peel and disperse the para-aramid fibers, promote the uniform growth of amorphous metal-organic frameworks on the surface of para-aramid nanofibers, and thus effectively improve the lithium-ion conductivity of the quasi-solid electrolyte.

[0035] In some embodiments, the protic solvent includes at least one of water, ethanol, diethyl ether, acetone, methanol, and isopropanol.

[0036] In this embodiment, the protonated solvent facilitates reprotonation exfoliation to promote uniform dispersion of para-aramid nanofibers, thereby obtaining a uniform and stable aramid nanofiber dispersion, which in turn improves the interfacial compatibility between para-aramid nanofibers and amorphous metal-organic frameworks and the structural stability of the quasi-solid electrolyte, and enhances the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0037] In some embodiments, the aramid nanofiber dispersion comprises a mixture of N,N-dimethylformamide and acetonitrile.

[0038] In this embodiment, limiting the type of solvent contained in the aramid nanofiber dispersion helps to promote the uniform dispersion of para-aramid nanofibers in a highly polar solvent environment, providing a stable reaction environment for the in-situ growth of amorphous metal-organic frameworks, thereby improving the lithium-ion conductivity of the quasi-solid electrolyte. If the solvent used in the solvent replacement treatment has low polarity, it is easy for the para-aramid nanofibers to agglomerate.

[0039] In some embodiments, the aramid nanofiber dispersion comprises a mixture of N,N-dimethylformamide and acetonitrile; the volume ratio of N,N-dimethylformamide to acetonitrile is 1:(1.9~2.1).

[0040] In this embodiment, limiting the volume ratio of N,N-dimethylformamide to acetonitrile within the above range helps to regulate the dispersion environment, ion diffusion rate, and coordination reaction rate of para-aramid nanofibers, thereby optimizing the interface structure and performance of the amorphous metal-organic framework and effectively improving the lithium-ion conductivity and cycle stability of the quasi-solid electrolyte.

[0041] In some embodiments, the method of mixing the aramid nanofiber dispersion, the metal salt and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture, adding the ligand solution, the buffer solution and the fourth mixture layer by layer from bottom to top into a container, and then allowing it to stand.

[0042] In this embodiment, by mixing the aramid nanofiber dispersion with the metal salt, the metal cations can be uniformly adsorbed onto the surface of the para-aramid nanofibers. Using the buffer solution as an intermediate layer can slow down the mixing rate of the metal cations and ligands, thereby achieving uniform and continuous growth of the amorphous metal-organic framework on the surface of the para-aramid nanofibers, and thus optimizing the lithium-ion conductivity and cycle stability of the quasi-solid electrolyte.

[0043] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, terephthalic acid is selected as the ligand.

[0044] In this embodiment, the coordination activity between terephthalic acid and nickel ions is high, and the type of ligand is limited to terephthalic acid, which helps to better match nickel ions and stably generate nickel-based amorphous metal-organic frameworks, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0045] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the metal salt is nickel acetate tetrahydrate.

[0046] In this embodiment, the metal salt is defined as nickel acetate tetrahydrate, which helps nickel ions to be uniformly adsorbed on the surface of para-aramid nanofibers and to uniformly generate nickel-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers through reaction with ligands, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0047] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the mass ratio of para-aramid nanofibers, ligand and metal salt is set to 1:(3.9~4.3):(3.9~4.3).

[0048] In this embodiment, limiting the mass ratio of para-aramid nanofibers, ligands, and metal salts to the above range helps to promote the full loading of the nickel-based amorphous organic framework, while optimizing the framework structure formed by the nickel-based amorphous organic framework and para-aramid nanofibers, thereby effectively improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0049] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the first solvent is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (1.9~2.1):1.

[0050] In this embodiment, limiting the type and volume ratio of the first solvent to the above range can promote the full and uniform mixing of ligands and metal ions, thereby uniformly growing an amorphous metal-organic framework on the surface of para-aramid nanofibers and improving the lithium-ion transport performance and cycle performance of the quasi-solid electrolyte.

[0051] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the buffer solution is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (0.9~1.1):(0.9~1.1).

[0052] In this embodiment, by limiting the type and volume ratio of the buffer solution, the mixing rate and reaction rate of the metal cation and ligand can be controlled to a suitable range to promote the uniform and stable growth of the amorphous metal-organic framework and effectively improve the lithium-ion transport performance and cycle performance.

[0053] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the volume ratio of the ligand solution, buffer solution and fourth mixture is set to (2.5~3.5):(1.5~2.5):(2.5~3.5).

[0054] In this embodiment, limiting the volume ratio of the ligand solution, buffer solution, and fourth mixture helps to further optimize the mixing rate and reaction rate of metal cations and ligands, optimize the distribution state of amorphous metal-organic frameworks on the surface of para-aramid nanofibers, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0055] In some embodiments, the method of mixing the aramid nanofiber dispersion, the metal salt and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture, adding the fourth mixture to the ligand solution and allowing it to stand.

[0056] In this embodiment, by mixing the aramid nanofiber dispersion and the metal salt, metal cations can be uniformly adsorbed onto the surface of the para-aramid nanofibers. By limiting the mixing method of the fourth mixture and the ligand solution to adding the fourth mixture to the ligand solution and allowing it to stand, the ligand and metal ions can be slowly mixed to selectively react on the surface of the para-aramid nanofibers to generate an amorphous metal-organic framework. The aforementioned technical effects help to simultaneously improve the lithium-ion conductivity and cycle performance of the quasi-solid-state electrolyte.

[0057] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, phenylphosphonic acid is selected as the ligand.

[0058] In this embodiment, phenylphosphonic acid has good coordination properties with iron ions, and the type of ligand is limited to phenylphosphonic acid, which helps to stably generate iron-based amorphous metal-organic framework, thereby effectively improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0059] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the metal salt is selected as ferric chloride hexahydrate.

[0060] In this embodiment, the metal salt is specified as ferric chloride hexahydrate, which can promote the uniform adsorption of iron ions on the surface of para-aramid nanofibers, thereby uniformly growing iron-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers and improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0061] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the mass ratio of para-aramid nanofibers, ligand and metal salt is set to 1:(6.8~9.3):(11.7~15.9).

[0062] In this embodiment, limiting the mass ratio of para-aramid nanofibers, ligands, and metal salts to the above range can promote the full loading of iron-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers, effectively improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0063] In some embodiments, when mixing the aramid nanofiber dispersion, metal salt, and ligand solution using the method described in the above embodiments, ethanol is selected as the first solvent.

[0064] In this embodiment, the first solvent is defined as ethanol, which helps to promote the coordination reaction between iron ions and ligands and stabilize the formation of an amorphous metal-organic framework, effectively improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0065] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the volume ratio of the ligand solution to the fourth mixture is set to (0.9~1.1):(0.9~1.1).

[0066] In this embodiment, limiting the volume ratio of the ligand solution to the fourth mixture to the above range can effectively control the local concentration, reduce the generation of by-products, and thereby improve the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0067] In some embodiments, the method of mixing the aramid nanofiber dispersion, the metal salt, and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture, and mixing the fourth mixture with the ligand solution to carry out a reaction.

[0068] In this embodiment, the aramid nanofiber dispersion and the metal salt are first mixed to promote the uniform adsorption of metal cations on the surface of the para-aramid nanofibers. Then, the fourth mixture and the ligand solution are mixed and reacted to promote rapid mixing of the fourth mixture and the ligand solution, so that the ligand can quickly contact the metal ions adsorbed on the surface of the para-aramid nanofibers. Through coordination reaction, an amorphous metal-organic framework is generated in situ, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0069] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the ligand is selected as 2-aminoterephthalic acid.

[0070] In this embodiment, 2-aminoterephthalic acid can simultaneously coordinate with iron ions and nickel ions. The type of ligand is limited to 2-aminoterephthalic acid, which helps to form an amorphous metal-organic framework with iron-nickel bimetallic nodes, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0071] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the metal salt is selected from ferrous chloride tetrahydrate and nickel acetate tetrahydrate.

[0072] In this embodiment, the aforementioned metal salts can enable iron and nickel ions to be uniformly adsorbed on the surface of para-aramid nanofibers, thereby uniformly growing an iron-nickel-based amorphous metal-organic framework on the surface of para-aramid nanofibers to improve the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0073] In some embodiments, the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, and when the metal salt is selected as ferrous chloride tetrahydrate and nickel acetate tetrahydrate, the mass ratio of ferrous chloride tetrahydrate to nickel acetate tetrahydrate is set to 1:(2.4~2.6).

[0074] In this embodiment, limiting the mass ratio of ferrous chloride tetrahydrate to nickel acetate tetrahydrate to the above range helps to optimize the structure of the iron-nickel-based amorphous metal-organic framework, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0075] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the mass ratio of para-aramid nanofibers, ligand and metal salt is set to 1:(3.0~4.1):(2.7~3.7).

[0076] In this embodiment, limiting the mass ratio of para-aramid nanofibers, ligands, and metal salts to the above range helps to grow amorphous metal-organic frameworks in situ on the surface of para-aramid nanofibers, and the amorphous metal-organic frameworks are fully loaded, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0077] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the first solvent is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (1.9~2.1):1.

[0078] In this embodiment, limiting the type and volume ratio of the first solvent can promote the simultaneous reaction of the ligand with iron ions and nickel ions to form coordination, thereby forming an iron-nickel-based amorphous metal-organic framework, which in turn improves the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0079] In some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the volume ratio of the ligand solution to the fourth mixture is set to (0.9~1.1):(0.9~1.1).

[0080] In this embodiment, limiting the volume ratio of the ligand solution to the fourth solution helps to regulate the mixing and reaction rates of the ligand, para-aramid nanofibers, and metal ions, ensuring the formation of an amorphous metal-organic framework to improve the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0081] In some embodiments, the electrolyte comprises at least one of lithium-sulfur electrolyte, lithium-ion secondary electrolyte, and ionic liquid, and contains lithium salt.

[0082] In this embodiment, the electrolyte is filled inside a three-dimensional framework composed of para-aramid nanofibers and an amorphous metal-organic framework, which helps to improve the lithium-ion conductivity of the quasi-solid electrolyte.

[0083] In some embodiments, the length of the para-aramid fiber is 0.6 μm to 1.8 μm; the aspect ratio of the para-aramid fiber is (10 to 45): 1.

[0084] In this embodiment, limiting the length, diameter, and aspect ratio of the para-aramid fibers helps to prepare para-aramid nanofibers of suitable size, thereby promoting the formation of a three-dimensional framework with both good mechanical properties and good pore structure. On the one hand, good mechanical properties are beneficial to improving the structural stability of the quasi-solid electrolyte, thereby suppressing dendrite formation and improving cycle performance. On the other hand, good pore structure is beneficial to the filling of amorphous metal-organic framework and electrolyte, thereby improving the lithium-ion transport performance of the quasi-solid electrolyte.

[0085] In some embodiments, the mass percentage of the electrolyte in the quasi-solid electrolyte is 1% to 5%.

[0086] In this embodiment, limiting the mass ratio of the electrolyte within the above range helps to form a continuous ion conduction pathway and effectively improve ion conductivity. On the other hand, it helps the quasi-solid electrolyte maintain good mechanical strength, suppress lithium dendrite puncture, and improve cycle stability.

[0087] Thirdly, embodiments of this application provide a battery comprising a positive electrode material, a negative electrode material, and an electrolyte, wherein the electrolyte is the electrolyte in the aforementioned technical solution or the electrolyte prepared by the preparation method of the quasi-solid-state electrolyte in the aforementioned technical solution.

[0088] In this embodiment, the battery contains the aforementioned quasi-solid electrolyte, thus possessing the advantages of high lithium-ion conductivity and good cycle stability.

[0089] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0090] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0091] Figure 1 The XRD patterns are of the quasi-solid-state electrolytes prepared in Example 1 and Comparative Example 1 of this application;

[0092] Figure 2 The images shown are TEM images of the quasi-solid-state electrolyte prepared in Example 1 of this application, where a is an HRTEM image and b is a SAED image.

[0093] Figure 3 The images shown are TEM images of the quasi-solid-state electrolyte prepared in Comparative Example 1 of this application, where a is an HRTEM image and b is a SAED image.

[0094] Figure 4 This is an EDS elemental distribution diagram of the quasi-solid electrolyte prepared in Example 1 of this application;

[0095] Figure 5 The image shows the EDS elemental distribution of the quasi-solid electrolyte prepared in Comparative Example 1 of this application.

[0096] Figure 6 Thermogravimetric analysis (TGA) curve of the quasi-solid electrolyte prepared in Example 1 of this application;

[0097] Figure 7 Electrochemical impedance spectroscopy of the quasi-solid electrolytes prepared in Example 1 and Comparative Example 1 of this application;

[0098] Figure 8 The graph shows the cycling performance of the quasi-solid electrolytes prepared in Example 1 and Comparative Example 1 of this application. Detailed Implementation

[0099] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0100] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0101] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0102] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0103] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0104] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0105] Quasi-solid electrolytes typically consist of a polymer backbone, lithium salt, and solvent, with a structure intermediate between liquid and all-solid electrolytes. Adding inorganic fillers to quasi-solid electrolytes can improve ion conduction efficiency to some extent; however, the poor interfacial compatibility between inorganic fillers and polymers results in persistent technical problems such as low lithium-ion conductivity and poor cycle stability.

[0106] To address the aforementioned technical problems, this application provides a quasi-solid-state electrolyte, its preparation method, and a battery. In this method, an amorphous metal-organic framework is generated in situ on the surface of para-aramid nanofibers, and the good interfacial compatibility between the para-aramid nanofibers and the amorphous metal-organic framework effectively improves the lithium-ion conductivity and cycle stability of the quasi-solid-state electrolyte.

[0107] In a first aspect, embodiments of this application provide a quasi-solid electrolyte, including an electrolyte, para-aramid nanofibers, and an amorphous metal-organic framework; wherein the amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

[0108] In this invention, an amorphous metal-organic framework (MOF) is used as a filler and para-aramid nanofibers are used as a polymer backbone to obtain a quasi-solid electrolyte. The amorphous MOF has a long-range disordered structure, which provides the following technical effects: (1) it makes the interfacial contact between the amorphous MOF and the para-aramid nanofibers closer; (2) it makes the surface activity of the amorphous MOF higher, which can promote the formation of strong chemical bonds between the two phases; (3) it gives the amorphous MOF good flexibility and structural adaptability, which can more uniformly disperse and transfer stress. These technical effects promote the interfacial coupling between the amorphous MOF and the para-aramid nanofibers and significantly improve their interfacial compatibility, thereby improving the lithium-ion conductivity and cycle stability of the quasi-solid electrolyte.

[0109] Para-aramid nanofibers and amorphous metal-organic frameworks together form a three-dimensional network structure. The electrolyte fills the pores of the three-dimensional network structure, which helps to form more and shorter lithium-ion transport pathways, thereby improving the lithium-ion conductivity of the quasi-solid electrolyte.

[0110] Furthermore, in some embodiments, the metal element in the amorphous metal-organic framework includes at least one of nickel and iron.

[0111] In the technical solutions of this application embodiment, the amorphous metal-organic framework containing the above-mentioned metal elements has good ionic conductivity, which can effectively improve the lithium-ion transport performance of the quasi-solid electrolyte.

[0112] Further, in some embodiments, the mass ratio of electrolyte, para-aramid nanofibers, and amorphous metal-organic framework is 1:(2.7~30.0):(12.2~69). Preferably, when the metal element in the amorphous metal-organic framework is nickel, the mass ratio of electrolyte, para-aramid nanofibers, and amorphous metal-organic framework is 1:(5.2~9.7):(13.0~22.7). Preferably, when the metal element in the amorphous metal-organic framework is iron, the mass ratio of electrolyte, para-aramid nanofibers, and amorphous metal-organic framework is 1:(2.7-3.5):(15.5-16.3). Preferably, when the metal elements in the amorphous metal-organic framework are iron and nickel, the mass ratio of electrolyte, para-aramid nanofibers, and amorphous metal-organic framework is 1:(5.6-6.8):(12.2-13.4).

[0113] In the technical solution of this application embodiment, the above-mentioned mass ratio range helps para-aramid nanofibers and amorphous metal-organic frameworks to jointly form a stable electrolyte skeleton. At the same time, the electrolyte fully fills the electrolyte skeleton, forming a good ion transport channel, thereby simultaneously improving the cycle stability and lithium-ion conductivity of the quasi-solid electrolyte.

[0114] Furthermore, in some embodiments, the electrolyte includes at least one of lithium-sulfur electrolyte, lithium-ion secondary electrolyte, and ionic liquid, and the electrolyte contains lithium salt.

[0115] In the technical solution of this application embodiment, the type of electrolyte is sufficient to ensure that it can conduct lithium ions and can be used in lithium batteries. Limiting the type of electrolyte to the above range is beneficial to improving the transport efficiency of lithium ions in quasi-solid electrolytes, thereby further improving lithium ion conductivity.

[0116] Secondly, embodiments of this application provide a method for preparing a quasi-solid-state electrolyte, comprising the following steps:

[0117] The ligand and the first solvent phase are mixed to obtain a ligand solution.

[0118] Para-aramid fibers, an alkali agent, and a second solvent are mixed to obtain a first mixture. Subsequently, the first mixture is mixed with a protic solvent to obtain a second mixture.

[0119] The second mixture is subjected to a first solid-liquid separation and solvent replacement treatment in sequence to replace the solvent in the second mixture with other solvents, thereby obtaining an aramid nanofiber dispersion containing para-aramid nanofibers.

[0120] A third mixture was obtained by mixing the aramid nanofiber dispersion, the metal salt and the ligand solution.

[0121] The third mixture undergoes a second solid-liquid separation to obtain the first membrane layer. Subsequently, the first membrane layer is wetted with electrolyte and dried to obtain a quasi-solid electrolyte.

[0122] The quasi-solid electrolyte includes an electrolyte, para-aramid nanofibers, and an amorphous metal-organic framework; the amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

[0123] In the technical solution of this application embodiment, the para-aramid fibers are first deprotonated using an alkali treatment, which helps promote the swelling, exfoliation, and refinement of the para-aramid fibers to obtain para-aramid nanofibers. Then, the para-aramid nanofibers are reprotonated and exfoliated using a protonating solvent, simultaneously promoting thorough and uniform dispersion of the fibers. After a first solid-liquid separation and solvent replacement treatment, an aramid nanofiber dispersion is obtained. By mixing and reacting the aramid nanofiber dispersion, metal salt, and ligand solution, it is beneficial to grow amorphous metal-organic frameworks in situ on the surface of the para-aramid nanofibers, while simultaneously promoting the uniform distribution of the amorphous metal-organic frameworks on the surface of the para-aramid nanofibers. Finally, a membrane material is formed through solid-liquid separation, and the membrane material is then wetted with an electrolyte and dried to fill the membrane material with an appropriate amount of electrolyte, resulting in a quasi-solid electrolyte. The aforementioned technical solution helps to generate uniformly distributed amorphous metal-organic frameworks in situ on the surface of para-aramid nanofibers. The amorphous metal-organic frameworks have close interfacial contact with para-aramid nanofibers, and strong chemical bonds can be formed between the two phases. At the same time, the amorphous metal-organic frameworks have good flexibility and structural adaptability, which can effectively improve the interfacial compatibility and coupling strength between the polymer skeleton and the inorganic filler, thereby improving the lithium-ion conductivity and cycle stability of the quasi-solid electrolyte.

[0124] Specifically, the para-aramid fiber, alkali agent, and second solvent are mixed by stirring for 6 to 8 days.

[0125] Specifically, a protic solvent is added to the first mixture to obtain the second mixture, which is also obtained by stirring, but the stirring time is very short, almost instantaneous.

[0126] Specifically, the aramid nanofiber dispersion, metal salt, and ligand solution are mixed by simultaneously performing ultrasound and stirring, wherein the stirring speed is 1000 rpm to 1500 rpm, and the ultrasound frequency is 20 kHz to 25 kHz.

[0127] Specifically, the first method of solid-liquid separation is centrifugation, and the second method of solid-liquid separation is vacuum filtration.

[0128] Specifically, the third mixture is washed with a mixture of N,N-dimethylformamide and chloroform, followed by a second solid-liquid separation and drying to obtain the first membrane layer.

[0129] Specifically, the solvent replacement treatment method is as follows: the product obtained from the first solid-liquid separation is denoted as the first precipitate. The first precipitate is first washed with an alcohol solvent to thoroughly remove water, yielding a second precipitate. Then, the second precipitate is washed with a third solvent to obtain a third precipitate. The third precipitate is mixed with a replacement solvent to obtain an aramid nanofiber dispersion, thus completing the solvent replacement. The third solvent is N,N-dimethylformamide, and the replacement solvent is selected from at least one of N,N-dimethylformamide and acetonitrile.

[0130] Specifically, during the electrolyte wetting and drying process, the wetting step is carried out in an inert atmosphere, and the drying temperature is 100℃~120℃. The wetting time and drying time are sufficient to ensure that the electrolyte content in the quasi-solid electrolyte meets the requirements.

[0131] Furthermore, in some embodiments, the ligand comprises at least one of terephthalic acid, phenylphosphonic acid, and 2-aminoterephthalic acid.

[0132] In the technical solutions of this application embodiment, limiting the types of ligands to the above range helps the ligands to undergo coordination reactions with metal ions adsorbed on the surface of para-aramid nanofibers, thereby generating an amorphous metal-organic framework in situ on the surface of para-aramid nanofibers, effectively improving the lithium-ion transport performance of the quasi-solid electrolyte.

[0133] Furthermore, in some embodiments, the alkali agent comprises at least one of potassium hydroxide, sodium hydroxide, potassium tert-butoxide, and sodium tert-butoxide.

[0134] In the technical solution of this application embodiment, the aforementioned alkaline agent facilitates deprotonation treatment, causing the amide groups (-NH-CO-) on the surface of the para-aramid fiber to deprotonate, thereby disrupting the hydrogen bond network between the aramid molecular chains. This promotes the swelling, exfoliation, and refinement of the para-aramid fiber, resulting in para-aramid nanofibers, which are then uniformly dispersed in a solvent. The preparation of uniformly dispersed para-aramid nanofibers is beneficial for the uniform growth of amorphous metal-organic frameworks, and further enhances the lithium-ion transport performance of the quasi-solid-state electrolyte.

[0135] Furthermore, in some embodiments, the metal salt comprises at least one of nickel acetate tetrahydrate, ferric chloride hexahydrate, and ferrous chloride tetrahydrate.

[0136] In the technical solution of this application embodiment, limiting the types of metal salts to the above-mentioned range helps to limit the types of metals, thereby ensuring the preparation of amorphous metal-organic frameworks; on the other hand, after the metal salts are dissolved, they can be continuously and stably electrolyzed to obtain metal cations, which can be uniformly adsorbed on the surface of para-aramid nanofibers, promoting the uniform distribution of amorphous metal-organic frameworks on the surface of para-aramid nanofibers, thereby improving the lithium-ion transport performance of the quasi-solid electrolyte.

[0137] Furthermore, in some embodiments, the mass ratio of para-aramid nanofibers, ligands, and metal salts is 1:(3.0~9.3):(2.7~15.9).

[0138] In the technical solution of this application embodiment, the mass ratio is limited to the above range. The metal cations obtained by metal salt electrolysis can be fully adsorbed on the surface of para-aramid nanofibers. At the same time, they can fully react with ligands to generate amorphous metal-organic frameworks, thereby promoting the uniform and full loading of amorphous metal-organic frameworks on the surface of para-aramid nanofibers to improve the lithium-ion transport performance of quasi-solid electrolytes.

[0139] Furthermore, in some embodiments, the mass ratio of para-aramid fiber to alkali agent is 1:(1.2~1.8).

[0140] In the technical solution of this application embodiment, by controlling the amount of alkali agent within the above-mentioned range, it is helpful to fully deprotonate the para-aramid fibers, thereby promoting their exfoliation and obtaining para-aramid nanofibers. This provides sufficient active sites for the in-situ growth of amorphous metal-organic frameworks, promotes the interfacial bonding between amorphous metal-organic frameworks and para-aramid nanofibers, and thus improves interfacial compatibility. In addition, reasonable control of the amount of alkali agent also helps to control the size of para-aramid nanofibers within a suitable range, so that the para-aramid nanofibers have good mechanical properties, thereby giving the quasi-solid electrolyte good mechanical strength.

[0141] Furthermore, in some embodiments, the first solvent comprises at least one of N,N-dimethylformamide, acetonitrile, and ethanol.

[0142] In the technical solution of this application embodiment, the above-mentioned solvent has good solubility for aromatic ligands, and at the same time helps to control the mixing rate of ligands with metal ions and para-aramid nanofibers, so as to limit the rate of coordination reaction, promote the uniform and stable growth of amorphous metal-organic frameworks on the surface of para-aramid nanofibers, thereby improving the lithium-ion transport performance and cycle performance of quasi-solid electrolyte.

[0143] Furthermore, in some embodiments, the second solvent comprises at least one of dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0144] In the technical solution of this application embodiment, the solvent is a strongly polar aprotic solvent, which can effectively penetrate and swell para-aramid fibers, weaken the hydrogen bond network between aramid fiber molecular chains, so as to fully peel and disperse para-aramid fibers, promote the uniform growth of amorphous metal-organic framework on the surface of para-aramid nanofibers, thereby effectively improving the lithium-ion conductivity of quasi-solid electrolyte.

[0145] Furthermore, in some embodiments, the protic solvent comprises at least one of water, ethanol, diethyl ether, acetone, methanol, and isopropanol.

[0146] In the technical solution of this application embodiment, reprotonation exfoliation is performed using the above-mentioned protic solvent to promote the uniform dispersion of para-aramid nanofibers, thereby obtaining a uniform and stable aramid nanofiber dispersion. The uniform dispersion of para-aramid nanofibers is beneficial to providing more active sites, thereby promoting the in-situ growth of amorphous metal-organic frameworks, and further improving the interfacial compatibility between para-aramid nanofibers and amorphous metal-organic frameworks and the structural stability of quasi-solid electrolytes, thereby improving the lithium-ion conductivity and cycle performance of quasi-solid electrolytes.

[0147] Furthermore, in some embodiments, the aramid nanofiber dispersion comprises a mixture of N,N-dimethylformamide and acetonitrile.

[0148] In the technical solution of this application embodiment, the solvent for dispersing para-aramid nanofibers is replaced with a mixture of N,N-dimethylformamide and acetonitrile through solid-liquid separation and solvent replacement treatment. This helps to promote the uniform dispersion of para-aramid nanofibers in a highly polar solvent environment, providing a stable reaction environment for the in-situ growth of amorphous metal-organic frameworks, thereby improving the lithium-ion conductivity of the quasi-solid electrolyte. If the solvent used in the solvent replacement treatment has low polarity, it is easy for the para-aramid nanofibers to agglomerate.

[0149] Furthermore, in some embodiments, the aramid nanofiber dispersion comprises a mixture of N,N-dimethylformamide and acetonitrile; the volume ratio of N,N-dimethylformamide to acetonitrile is 1:(1.9~2.1).

[0150] In the technical solutions of this application embodiment, limiting the volume ratio of N,N-dimethylformamide to acetonitrile within the above range helps to regulate the dispersion environment, ion diffusion rate and coordination reaction rate of para-aramid nanofibers, thereby optimizing the interface structure and performance of amorphous metal-organic frameworks and effectively improving the lithium-ion conductivity and cycle stability of quasi-solid electrolytes.

[0151] Furthermore, in some embodiments, the electrolyte comprises at least one of lithium-sulfur electrolyte, lithium-ion secondary electrolyte, and ionic liquid, and the electrolyte contains lithium salt.

[0152] In the technical solution of this application embodiment, the electrolyte is filled inside the three-dimensional skeleton composed of para-aramid nanofibers and amorphous metal-organic framework, which helps to improve the lithium-ion conductivity of the quasi-solid electrolyte.

[0153] Furthermore, in some embodiments, the length of the para-aramid fiber is 0.6 μm to 1.8 μm; the aspect ratio of the para-aramid fiber is (10 to 45):1.

[0154] In the technical solution of this application embodiment, limiting the length, diameter and aspect ratio of para-aramid fibers helps to prepare para-aramid nanofibers of suitable size, thereby promoting the formation of a three-dimensional framework with good mechanical properties and good pore structure. On the one hand, good mechanical properties are beneficial to improving the structural stability of the quasi-solid electrolyte, thereby suppressing dendrite formation and improving cycle performance. On the other hand, good pore structure is beneficial to the filling of amorphous metal-organic framework and electrolyte, thereby improving the lithium-ion transport performance of the quasi-solid electrolyte.

[0155] Specifically, the diameter of the para-aramid fiber is 40nm~60nm.

[0156] Furthermore, in some embodiments, the mass percentage of the electrolyte in the quasi-solid electrolyte is 1% to 5%. Preferably, the mass percentage of the electrolyte in the quasi-solid electrolyte is 3% to 5%.

[0157] In the technical solution of this application embodiment, limiting the mass ratio of the electrolyte within the above range helps to form a continuous ion conduction pathway and effectively improve ion conductivity; on the other hand, it helps the quasi-solid electrolyte maintain good mechanical strength, suppress lithium dendrite puncture, and improve cycle stability.

[0158] Furthermore, in some embodiments, the method of mixing the aramid nanofiber dispersion, the metal salt, and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture, adding the ligand solution, the buffer solution, and the fourth mixture layer by layer from bottom to top into a container, and then allowing it to stand.

[0159] In the technical solution of this application embodiment, an amorphous metal-organic framework is grown in situ on the surface of para-aramid nanofibers using a liquid-liquid interface diffusion method. This method mixes the aramid nanofiber dispersion with a metal salt, which allows metal cations to be uniformly adsorbed on the surface of the para-aramid nanofibers. Using a buffer solution as an intermediate layer can slow down the mixing rate of the metal cations and ligands, thereby achieving uniform and continuous growth of the amorphous metal-organic framework on the surface of the para-aramid nanofibers, and thus optimizing the lithium-ion conductivity and cycle stability of the quasi-solid electrolyte.

[0160] Specifically, the aramid nanofiber dispersion and the metal salt are mixed by ultrasonic stirring for 10-14 hours to ensure that the metal cations are uniformly adsorbed on the surface of the para-aramid nanofibers, thus obtaining the fourth mixture.

[0161] Specifically, after adding the ligand solution, buffer solution and fourth mixture layer by layer from bottom to top into the container, it can be left to stand at room temperature (20℃~40℃) for 22h~26h. During the standing process, the metal cations and ligands undergo coordination reaction, and an amorphous metal-organic framework is obtained by in-situ growth on the surface of para-aramid nanofibers.

[0162] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, terephthalic acid is selected as the ligand.

[0163] In the technical solution of this application embodiment, the coordination activity between terephthalic acid and nickel ions is high, and the type of ligand is limited to terephthalic acid, which helps to stably generate nickel-based amorphous metal-organic framework, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0164] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the metal salt is nickel acetate tetrahydrate.

[0165] In the technical solution of this application embodiment, when using the liquid-liquid interface diffusion method to grow an amorphous metal-organic framework in situ on the surface of para-aramid nanofibers, the type of metal salt is limited to nickel acetate tetrahydrate, which helps nickel ions to be uniformly adsorbed on the surface of para-aramid nanofibers and to uniformly generate nickel-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers through reaction with ligands, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0166] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the mass ratio of para-aramid nanofibers, ligand, and metal salt is set to 1:(3.9~4.3):(3.9~4.3).

[0167] In the technical solution of this application embodiment, limiting the mass ratio of para-aramid nanofibers, ligands and metal salts to the above range helps to promote the full loading of nickel-based amorphous organic frameworks, while optimizing the framework structure formed by the nickel-based amorphous organic frameworks and para-aramid nanofibers, thereby effectively improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0168] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the ligand is terephthalic acid, the metal salt is nickel acetate tetrahydrate, and the mass ratio of para-aramid nanofibers, ligand, and metal salt is set to 1:(3.9~4.3):(3.9~4.3).

[0169] In the technical solution of this application embodiment, when using the liquid-liquid interface diffusion method, the types of ligands and metal salts, as well as the mass ratio of para-aramid nanofibers, ligands and metal salts are simultaneously limited. This helps to uniformly and stably grow nickel-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers, while ensuring uniform loading of the amorphous metal-organic frameworks, so as to further improve the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0170] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the first solvent is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (1.9~2.1):1.

[0171] In the technical solution of this application embodiment, limiting the type and volume ratio of the first solvent to the above range can promote the full and uniform mixing of ligands and metal ions, thereby uniformly growing an amorphous metal-organic framework on the surface of para-aramid nanofibers and improving the lithium-ion transport performance and cycle performance of the quasi-solid electrolyte.

[0172] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the buffer solution is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (0.9~1.1):(0.9~1.1).

[0173] In the technical solution of this application embodiment, by limiting the type and volume ratio of the buffer solution, the mixing rate and reaction rate of the metal cation and ligand can be controlled to a suitable range, so as to promote the uniform and stable growth of the amorphous metal-organic framework and effectively improve the lithium-ion transport performance and cycle performance.

[0174] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the volume ratio of the ligand solution, buffer solution and fourth mixture is (2.5~3.5):(1.5~2.5):(2.5~3.5).

[0175] In the technical solution of this application embodiment, limiting the volume ratio of ligand solution, buffer solution and fourth mixture helps to further optimize the mixing rate and reaction rate of metal cations and ligands, optimize the distribution state of amorphous metal-organic framework on the surface of para-aramid nanofibers, thereby improving the lithium-ion conductivity and cycle performance of quasi-solid electrolyte.

[0176] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the aramid nanofiber dispersion contains a mixture of N,N-dimethylformamide and acetonitrile at a volume ratio of 1:(1.9~2.1), the first solvent in the ligand solution is a mixture of N,N-dimethylformamide and acetonitrile at a volume ratio of (1.9~2.1):1, and the buffer solution is a mixture of N,N-dimethylformamide and acetonitrile, with a volume ratio of N,N-dimethylformamide to acetonitrile of (0.9~1.1):(0.9~1.1).

[0177] In the above-mentioned preferred technical solution, when using the liquid-liquid interface diffusion method to grow an amorphous metal-organic framework in situ on the surface of para-aramid nanofibers, limiting the solvent type and volume ratio within the above range allows for the utilization of diffusion kinetics to promote the slow diffusion and uniform mixing of ligands and metal ions. This enables precise control of the mixing rate and reaction rate between the ligands and the para-aramid nanofibers adsorbed with metal ions, generating a uniformly loaded amorphous metal-organic framework on the surface of the para-aramid nanofibers. This optimizes the structure of the quasi-solid electrolyte and effectively improves the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0178] Furthermore, in some embodiments, the method of mixing the aramid nanofiber dispersion, the metal salt, and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture, adding the fourth mixture to the ligand solution, and allowing it to stand.

[0179] In the technical solution of this application embodiment, by mixing the aramid nanofiber dispersion and the metal salt, metal cations can be uniformly adsorbed onto the surface of the para-aramid nanofibers. By limiting the mixing method of the fourth mixture and the ligand solution to adding the fourth mixture to the ligand solution and allowing it to stand, the ligand and metal ions can be slowly mixed, and the reaction rate can be controlled to selectively react on the surface of the para-aramid nanofibers to generate an amorphous metal-organic framework. The aforementioned technical effects help to control the structure of the amorphous metal-organic framework and its distribution on the surface of the para-aramid nanofibers, thereby simultaneously improving the lithium-ion conductivity and cycle performance of the quasi-solid-state electrolyte.

[0180] Specifically, when mixing the aramid nanofiber dispersion, metal salt, and ligand solution using the method described in the above embodiments, the fourth mixture is added to the ligand solution and then allowed to stand at room temperature (20℃~40℃) for 10h~14h.

[0181] Specifically, when mixing the aramid nanofiber dispersion, metal salt, and ligand solution using the method described in the above embodiments, the fourth mixture is added to the ligand solution dropwise at a rate of 3.0 mL / min to 5.0 mL / min.

[0182] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, phenylphosphonic acid is selected as the ligand.

[0183] In the technical solution of this application embodiment, phenylphosphonic acid has good coordination performance with iron ions, and the type of ligand is limited to phenylphosphonic acid, which helps to stably generate iron-based amorphous metal-organic framework, thereby effectively improving the lithium-ion conductivity and cycle performance of quasi-solid electrolyte.

[0184] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the metal salt is selected as ferric chloride hexahydrate.

[0185] In the technical solution of this application embodiment, the type of metal salt is limited to ferric chloride hexahydrate, which can promote the uniform adsorption of iron ions on the surface of para-aramid nanofibers, thereby uniformly growing iron-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers and improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0186] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the mass ratio of para-aramid nanofibers, ligand and metal salt is set to 1:(6.8~9.3):(11.7~15.9).

[0187] In the technical solution of this application embodiment, limiting the mass ratio of para-aramid nanofibers, ligands and metal salts to the above range can promote the full loading of iron-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers, effectively improving the lithium-ion conductivity and cycle performance of quasi-solid electrolytes.

[0188] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the ligand is selected as phenylphosphonic acid, the metal salt is selected as ferric chloride hexahydrate, and the mass ratio of para-aramid nanofiber, ligand and metal salt is set to 1: (6.8~9.3): (11.7~15.9).

[0189] In the aforementioned preferred technical solution, an iron-based amorphous metal-organic framework is generated in situ on the surface of para-aramid nanofibers by first adding the framework dropwise and then allowing it to stand. Simultaneously, the types of ligands and metal salts, as well as the mass ratio of para-aramid nanofibers, ligands, and metal salts, are limited. This approach promotes the stable formation and uniform, fully loaded iron-based amorphous metal-organic framework, thereby effectively improving the lithium-ion conductivity and cycle performance of the quasi-solid-state electrolyte.

[0190] Furthermore, in some embodiments, when mixing the aramid nanofiber dispersion, metal salt, and ligand solution using the method described in the above embodiments, ethanol is selected as the first solvent.

[0191] In the technical solution of this application embodiment, by limiting the first solvent to ethanol, a relatively mild coordination environment can be provided while fully dissolving the ligand, thereby promoting the coordination reaction between iron ions and ligands and stably forming an amorphous metal-organic framework, effectively improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0192] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the volume ratio of the ligand solution to the fourth mixture is set to (0.9~1.1):(0.9~1.1).

[0193] In the technical solution of this application embodiment, limiting the volume ratio of the ligand solution to the fourth mixture to the above range can effectively control the local concentration, reduce the generation of by-products, and thereby improve the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0194] Furthermore, in some embodiments, the method of mixing the aramid nanofiber dispersion, the metal salt, and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture, and mixing the fourth mixture with the ligand solution to carry out a reaction.

[0195] In the technical solution of this application embodiment, the aramid nanofiber dispersion and the metal salt are first mixed to promote the uniform adsorption of metal cations on the surface of para-aramid nanofibers. Then, the fourth mixture and the ligand solution are mixed and reacted to promote the rapid mixing of the fourth mixture and the ligand solution, so that the ligand can quickly contact the metal ions adsorbed on the surface of para-aramid nanofibers. Through coordination reaction, an amorphous metal-organic framework is generated in situ, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0196] Specifically, when mixing the aramid nanofiber dispersion, metal salt, and ligand solution using the method described in the above embodiments, the two solutions are rapidly mixed by directly pouring the fourth mixture into the ligand solution under stirring conditions.

[0197] Specifically, when mixing the aramid nanofiber dispersion, metal salt, and ligand solution using the method described in the above embodiments, the fourth mixture and the ligand solution are mixed under stirring conditions, and then stirred and reacted at room temperature (20℃~40℃) for 0.8h~1.2h.

[0198] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the ligand is selected as 2-aminoterephthalic acid.

[0199] In the technical solution of this application embodiment, 2-aminoterephthalic acid can simultaneously form coordination with iron ions and nickel ions. The type of ligand is limited to 2-aminoterephthalic acid, which helps to form an amorphous metal-organic framework with iron-nickel bimetallic nodes, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0200] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the metal salt is selected as ferrous chloride tetrahydrate and nickel acetate tetrahydrate. Preferably, the mass ratio of ferrous chloride tetrahydrate to nickel acetate tetrahydrate is 1:(2.4~2.6).

[0201] In the technical solution of this application embodiment, the aforementioned metal salts enable iron and nickel ions to be uniformly adsorbed on the surface of para-aramid nanofibers, thereby uniformly growing an iron-nickel-based amorphous metal-organic framework on the surface of the para-aramid nanofibers, thus improving the lithium-ion conductivity and cycle performance of the quasi-solid-state electrolyte. Furthermore, limiting the mass ratio of ferrous chloride tetrahydrate to nickel acetate tetrahydrate helps to further optimize the structure of the iron-nickel-based amorphous metal-organic framework, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid-state electrolyte.

[0202] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt and ligand solution are mixed using the method described in the above embodiments, the mass ratio of para-aramid nanofibers, ligand and metal salt is set to 1:(3.0~4.1):(2.7~3.7).

[0203] In the technical solution of this application embodiment, limiting the mass ratio of para-aramid nanofibers, ligands and metal salts to the above range helps to grow amorphous metal-organic frameworks in situ on the surface of para-aramid nanofibers, and the amorphous metal-organic frameworks are fully loaded, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0204] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the ligand is selected as 2-aminoterephthalic acid, the metal salt is selected as ferrous chloride tetrahydrate and nickel acetate tetrahydrate, the mass ratio of ferrous chloride tetrahydrate to nickel acetate tetrahydrate is set to 1:(2.4~2.6), and the mass ratio of para-aramid nanofiber, ligand, and metal salt is set to 1:(3.0~4.1):(2.7~3.7).

[0205] In the technical solution of this application embodiment, the fourth mixture and ligand solution are rapidly mixed by direct pouring and then reacted. At the same time, the types of ligands and metal salts, as well as the mass ratio of para-aramid nanofibers, ligands and metal salts are limited, which helps to rapidly generate a uniform and fully loaded amorphous metal-organic framework in situ on the surface of para-aramid nanofibers, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0206] Furthermore, in some embodiments, the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments. The first solvent is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (1.9~2.1):1.

[0207] In the technical solution of this application embodiment, limiting the type and volume ratio of the first solvent can promote the simultaneous reaction of the ligand with iron ions and nickel ions to form coordination, thereby forming an iron-nickel-based amorphous metal-organic framework, and thus improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0208] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the volume ratio of the ligand solution to the fourth mixture is set to (0.9~1.1):(0.9~1.1).

[0209] In the technical solution of this application embodiment, limiting the volume ratio of the ligand solution to the fourth solution helps to regulate the mixing rate and reaction rate of the ligand, para-aramid nanofibers and metal ions, ensuring the generation of an amorphous metal-organic framework, thereby improving the lithium-ion conductivity and cycle performance of the quasi-solid electrolyte.

[0210] Furthermore, in some embodiments, when the aramid nanofiber dispersion, metal salt, and ligand solution are mixed using the method described in the above embodiments, the aramid nanofiber dispersion contains a mixture of N,N-dimethylformamide and acetonitrile at a volume ratio of 1:(1.9~2.1), the first solvent in the ligand solution is a mixture of N,N-dimethylformamide and acetonitrile at a volume ratio of (1.9~2.1):1, and the volume ratio of the ligand solution to the fourth mixture is (0.9~1.1):(0.9~1.1).

[0211] In the above preferred technical solution, the fourth mixture and the ligand solution are rapidly mixed by direct pouring, and then an amorphous metal-organic framework is generated in situ on the surface of para-aramid nanofibers through reaction. At the same time, the type and volume ratio of the solvent are limited, which helps to provide a stable and suitable reaction environment and promote the generation of amorphous metal-organic framework.

[0212] Thirdly, embodiments of this application provide a battery comprising a positive electrode material, a negative electrode material, and an electrolyte, wherein the electrolyte is the electrolyte in the aforementioned technical solution or the electrolyte prepared by the preparation method of the quasi-solid-state electrolyte in the aforementioned technical solution.

[0213] In the technical solution of this application embodiment, the battery contains the above-mentioned quasi-solid electrolyte, and thus has the advantages of high lithium-ion conductivity and good cycle stability.

[0214] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0215] Some of the materials used in the examples and comparative examples are as follows:

[0216] Lithium-sulfur electrolyte: Model LS-002, purchased from Suzhou Duoduo Chemical Technology Co., Ltd. This lithium-sulfur electrolyte contains 1 mol / L lithium bis(trifluoromethanesulfonyl)imide, 1% lithium nitrate by mass, and solvent. The solvent is obtained by mixing ethylene glycol dimethyl ether and 1,3-dioxolane in a volume ratio of 1:1.

[0217] Lithium-ion secondary electrolyte: Model LB-002, purchased from Suzhou Duoduo Chemical Technology Co., Ltd. This lithium-ion secondary electrolyte contains 1 mol / L lithium hexafluorophosphate. The solvent is obtained by mixing dimethyl carbonate, ethylene carbonate and ethyl methyl carbonate in a volume ratio of 1:1:1.

[0218] Ionic liquid: Prepared in-house, containing 0.8 mol / L lithium bis(trifluoromethanesulfonyl)imide, with 1-ethyl-3-methylimidazolium-bis(trifluoromethanesulfonyl)imide salt as the solvent, purchased from Suzhou Duoduo Chemical Technology Co., Ltd.

[0219] Short-cut para-aramid fiber-1: 1.2 μm in length and 50 nm in diameter (aspect ratio 24:1), purchased from DuPont deNemours, Inc.

[0220] Short-cut para-aramid fiber-2: 0.6 μm in length and 60 nm in diameter (aspect ratio 10:1), purchased from DuPont deNemours, Inc.

[0221] Short-cut para-aramid fiber-3: 1.8 μm in length and 40 nm in diameter (45:1 aspect ratio), purchased from DuPont deNemours, Inc.

[0222] I. Preparation Method

[0223] Example 1

[0224] This embodiment provides a quasi-solid electrolyte, including a lithium-sulfur electrolyte, para-aramid nanofibers, and a nickel-based amorphous metal-organic framework; wherein the nickel-based amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

[0225] The preparation method of quasi-solid electrolytes includes the following steps:

[0226] S1, 8 mL of N,N-dimethylformamide is mixed with 4 mL of acetonitrile to obtain the first solvent, and 80 mg of terephthalic acid is mixed with the first solvent to obtain the ligand solution.

[0227] S2, 1g of chopped para-aramid fibers-1, 1.5g of potassium hydroxide and 500mL of dimethyl sulfoxide were mixed and magnetically stirred at 25℃ for 7 days to obtain a dark red first mixture containing para-aramid nanofibers at a concentration of 2mg / mL. Then, 10mL of the first mixture was taken and 50mL of distilled water was added for protonation exfoliation to obtain a second mixture.

[0228] S3. The second mixture was centrifuged (10000 rpm, 5 min) to remove the supernatant, yielding the first precipitate. The first precipitate was washed with anhydrous ethanol to remove residual water, yielding the second precipitate. The second precipitate was then washed with N,N-dimethylformamide to obtain the third precipitate. Finally, 4 mL of the N,N-dimethylformamide mixture was mixed with 8 mL of acetonitrile and the third precipitate to redisperse the para-aramid nanofibers, resulting in an aramid nanofiber dispersion.

[0229] The method for washing the first precipitate with anhydrous ethanol is as follows: Disperse the first precipitate thoroughly with 50 mL of anhydrous ethanol, then centrifuge (10000 rpm, 5 min), remove the supernatant, and repeat the above step 3 times. The method for washing the second precipitate with N,N-dimethylformamide is as follows: Disperse the second precipitate thoroughly with 50 mL of N,N-dimethylformamide, then centrifuge (10000 rpm, 5 min), remove the supernatant, and repeat the above step 3 times.

[0230] S4. Mix 12 mL of the aramid nanofiber dispersion prepared in step S3 with 80 mg of nickel acetate tetrahydrate, and stir under ultrasonic (25 kHz) conditions for 12 h to allow nickel ions to be uniformly adsorbed on the surface of the para-aramid nanofibers, obtaining the fourth mixture. Mix 4 mL of N,N-dimethylformamide with 4 mL of acetonitrile to obtain a buffer solution. Add 12 mL of ligand solution, 8 mL of buffer solution, and 12 mL of the fourth mixture layer by layer from bottom to top into the container, and then let it stand at 30 °C in air for 24 h to grow a nickel-based amorphous metal-organic framework in situ on the surface of the para-aramid nanofibers, obtaining the third mixture.

[0231] S5, the third mixture is vacuum filtered to obtain a filter cake, which is then filtered using a mixture of N,N-dimethylformamide and chloroform (V... DMF :V 三氯甲烷 The filter cake was washed with a ratio of 1:1 and then dried at 110°C to obtain the first membrane layer. Subsequently, the first membrane layer was placed in an argon glove box to immerse in lithium-sulfur electrolyte for 2 seconds, and then removed and dried at 110°C to control the mass ratio of lithium-sulfur electrolyte to 5% to obtain a quasi-solid electrolyte.

[0232] Example 2

[0233] This embodiment provides a quasi-solid-state electrolyte, which differs from Embodiment 1 in that the metal element in the amorphous metal-organic framework is iron, and the mass ratio of the electrolyte, para-aramid nanofibers, and amorphous metal-organic framework is different. Specifically, the quasi-solid-state electrolyte includes a lithium-sulfur electrolyte, para-aramid nanofibers, and an iron-based amorphous metal-organic framework; wherein the iron-based amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

[0234] Compared with Example 1, the preparation method of the quasi-solid electrolyte differs in the mixing method of the aramid nanofiber dispersion, metal salt, and ligand solution, and includes the following steps:

[0235] S1, 158 mg of phenylphosphonic acid and 30 mL of ethanol were mixed to obtain a ligand solution.

[0236] S2, 1g of chopped para-aramid fibers-1, 1.5g of potassium hydroxide and 500mL of dimethyl sulfoxide were mixed and magnetically stirred at 25℃ for 7 days to obtain a dark red first mixture containing para-aramid nanofibers at a concentration of 2mg / mL. Then, 10mL of the first mixture was taken and 50mL of distilled water was added for protonation exfoliation to obtain a second mixture.

[0237] S3. The second mixture is centrifuged (10000 rpm, 5 min) to remove the supernatant, yielding the first precipitate. The first precipitate is washed with anhydrous ethanol (using the same washing method as in Example 1) to thoroughly remove residual water, yielding the second precipitate. The second precipitate is then washed with N,N-dimethylformamide (using the same washing method as in Example 1) to obtain the third precipitate. Finally, 10 mL of the mixture of N,N-dimethylformamide and 20 mL of acetonitrile is mixed with the third precipitate to redisperse the para-aramid nanofibers, yielding an aramid nanofiber dispersion.

[0238] S4. Mix 30 mL of the aramid nanofiber dispersion prepared in step S3 with 270 mg of ferric chloride hexahydrate, and stir under ultrasonic (25 kHz) conditions for 12 h to allow iron ions to be uniformly adsorbed on the surface of the para-aramid nanofibers, resulting in a fourth mixture. Add the fourth mixture dropwise to the ligand solution under stirring conditions at a dropping rate of 4 mL / min, and then let it stand at 30 °C in air for 12 h to allow in-situ growth of an iron-based amorphous metal-organic framework on the surface of the para-aramid nanofibers, resulting in a third mixture.

[0239] S5, the third mixture is vacuum filtered to obtain a filter cake, which is then filtered using a mixture of N,N-dimethylformamide and chloroform (V... DMF :V 三氯甲烷The filter cake was washed with a ratio of 1:1 and then dried at 110°C to obtain the first membrane layer. Subsequently, the first membrane layer was placed in an argon glove box to immerse in lithium-sulfur electrolyte for 2 seconds, and then removed and dried at 110°C to control the mass ratio of lithium-sulfur electrolyte to 5% to obtain a quasi-solid electrolyte.

[0240] Example 3

[0241] This embodiment provides a quasi-solid-state electrolyte, which differs from Embodiment 1 in that the metal elements in the amorphous metal-organic framework are iron and nickel, and the mass ratio of the lithium-sulfur electrolyte, para-aramid nanofibers, and the amorphous metal-organic framework is different. Specifically, the quasi-solid-state electrolyte includes a lithium-sulfur electrolyte, para-aramid nanofibers, and an iron-nickel-based amorphous metal-organic framework; wherein the iron-nickel-based amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

[0242] Compared with Example 1, the preparation method of the quasi-solid electrolyte differs in the mixing method of the aramid nanofiber dispersion, metal salt, and ligand solution, and includes the following steps:

[0243] S1, 20 mL of N,N-dimethylformamide and 10 mL of acetonitrile are mixed to obtain the first solvent. 70 mg of 2-aminoterephthalic acid and 30 mL of the first solvent are mixed to obtain the ligand solution.

[0244] S2, 1g of chopped para-aramid fibers-1, 1.5g of potassium hydroxide and 500mL of dimethyl sulfoxide were mixed and magnetically stirred at 25℃ for 7 days to obtain a dark red first mixture containing para-aramid nanofibers at a concentration of 2mg / mL. Then, 10mL of the first mixture was taken and 50mL of distilled water was added for protonation exfoliation to obtain a second mixture.

[0245] S3. The second mixture is centrifuged (10000 rpm, 5 min) to remove the supernatant, yielding the first precipitate. The first precipitate is washed with anhydrous ethanol (using the same washing method as in Example 1) to thoroughly remove residual water, yielding the second precipitate. The second precipitate is then washed with N,N-dimethylformamide (using the same washing method as in Example 1) to obtain the third precipitate. Finally, 10 mL of the mixture of N,N-dimethylformamide and 20 mL of acetonitrile is mixed with the third precipitate to redisperse the para-aramid nanofibers, yielding an aramid nanofiber dispersion.

[0246] S4, 30 mL of aramid nanofiber dispersion, 18 mg of ferrous chloride tetrahydrate, and 45 mg of nickel acetate tetrahydrate were mixed and stirred under ultrasonic (25 kHz) conditions for 12 h to allow iron and nickel ions to be uniformly adsorbed on the surface of para-aramid nanofibers, resulting in a fourth mixture. Under stirring, the fourth mixture was poured into a ligand solution, and then stirred continuously at 30 °C in air for 1 h to grow an iron-nickel-based amorphous metal-organic framework in situ on the surface of the para-aramid nanofibers, resulting in a third mixture.

[0247] S5, the third mixture is vacuum filtered to obtain a filter cake, which is then filtered using a mixture of N,N-dimethylformamide and chloroform (V... DMF :V 三氯甲烷 The filter cake was washed with a ratio of 1:1 and then dried at 110°C to obtain the first membrane layer. Subsequently, the first membrane layer was placed in an argon glove box to immerse in lithium-sulfur electrolyte for 2 seconds, and then removed and dried at 110°C to control the mass ratio of lithium-sulfur electrolyte to 5% to obtain a quasi-solid electrolyte.

[0248] Example 4

[0249] The difference between this embodiment and Embodiment 1 is that the short-cut para-aramid nanofiber-1 is replaced with short-cut para-aramid nanofiber-2, and the lithium-sulfur electrolyte is replaced with a lithium-ion secondary electrolyte.

[0250] The preparation method of quasi-solid electrolytes includes the following steps:

[0251] S1, 8 mL of N,N-dimethylformamide and 4 mL of acetonitrile are mixed to obtain the first solvent, and 80 mg of terephthalic acid is mixed with the first solvent to obtain the ligand solution.

[0252] S2, 1g of chopped para-aramid fibers-2, 1.2g of potassium hydroxide and 500mL of dimethyl sulfoxide were mixed and magnetically stirred at 25℃ for 6 days to obtain a dark red first mixture containing para-aramid nanofibers at a concentration of 2mg / mL. Then, 10mL of the first mixture was taken and 50mL of distilled water was added for protonation exfoliation to obtain a second mixture.

[0253] S3. The second mixture is centrifuged (10000 rpm, 5 min) to remove the supernatant, yielding the first precipitate. The first precipitate is washed with anhydrous ethanol (using the same washing method as in Example 1) to thoroughly remove residual water, yielding the second precipitate. The second precipitate is then washed with N,N-dimethylformamide (using the same washing method as in Example 1) to obtain the third precipitate. Finally, 4 mL of the mixture of N,N-dimethylformamide and 8 mL of acetonitrile is mixed with the third precipitate to redisperse the para-aramid nanofibers, yielding an aramid nanofiber dispersion.

[0254] S4. Aramid nanofiber dispersion and 80 mg of nickel acetate tetrahydrate were mixed and stirred under ultrasonic (20 kHz) conditions for 10 h to allow nickel ions to be uniformly adsorbed on the surface of para-aramid nanofibers, resulting in a fourth mixture. 4 mL of N,N-dimethylformamide was mixed with 4 mL of acetonitrile to obtain a buffer solution. 12 mL of ligand solution, 8 mL of buffer solution, and 12 mL of the fourth mixture were added layer by layer from bottom to top into the container. The mixture was then allowed to stand at 20 °C in air for 26 h to allow in-situ growth of nickel-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers, resulting in a third mixture.

[0255] S5, the third mixture is vacuum filtered to obtain a filter cake, which is then filtered using a mixture of N,N-dimethylformamide and chloroform (V... DMF :V 三氯甲烷 The filter cake was washed with a ratio of 1:1 and then dried at 110°C to obtain the first membrane layer. Subsequently, the first membrane layer was immersed in lithium-ion secondary electrolyte in an argon glove box for 1 second, and then removed and dried at 100°C to control the mass ratio of lithium-ion secondary electrolyte to 1% to obtain a quasi-solid electrolyte.

[0256] Example 5

[0257] The difference between this embodiment and Embodiment 1 is that the short-cut para-aramid nanofiber-1 is replaced with short-cut para-aramid nanofiber-3, and the lithium-sulfur electrolyte is replaced with an ionic liquid.

[0258] The preparation method of quasi-solid electrolytes includes the following steps:

[0259] S1, 8 mL of N,N-dimethylformamide and 4 mL of acetonitrile are mixed to obtain the first solvent, and 80 mg of terephthalic acid is mixed with the first solvent to obtain the ligand solution.

[0260] S2, 1g of chopped para-aramid fibers-3, 1.8g of potassium hydroxide and 500mL of dimethyl sulfoxide were mixed and magnetically stirred at 25℃ for 8 days to obtain a dark red first mixture containing para-aramid nanofibers at a concentration of 2mg / mL. Then, 10mL of the first mixture was taken and 50mL of distilled water was added for protonation exfoliation to obtain a second mixture.

[0261] S3. The second mixture is centrifuged (10000 rpm, 5 min) to remove the supernatant, yielding the first precipitate. The first precipitate is washed with anhydrous ethanol (using the same washing method as in Example 1) to thoroughly remove residual water, yielding the second precipitate. The second precipitate is then washed with N,N-dimethylformamide (using the same washing method as in Example 1) to obtain the third precipitate. Finally, 4 mL of the mixture of N,N-dimethylformamide and 8 mL of acetonitrile is mixed with the third precipitate to redisperse the para-aramid nanofibers, yielding an aramid nanofiber dispersion.

[0262] S4. Aramid nanofiber dispersion and 80 mg of nickel acetate tetrahydrate were mixed and stirred under ultrasonic (22.5 kHz) conditions for 14 h to allow nickel ions to be uniformly adsorbed on the surface of para-aramid nanofibers, resulting in a fourth mixture. 4 mL of N,N-dimethylformamide was mixed with 4 mL of acetonitrile to obtain a buffer solution. 12 mL of ligand solution, 8 mL of buffer solution, and 12 mL of the fourth mixture were added layer by layer from bottom to top into the container. The mixture was then allowed to stand at 40 °C in air for 22 h to allow in-situ growth of nickel-based amorphous metal-organic frameworks on the surface of para-aramid nanofibers, resulting in a third mixture.

[0263] S5, the third mixture is vacuum filtered to obtain a filter cake, which is then filtered using a mixture of N,N-dimethylformamide and chloroform (V... DMF :V 三氯甲烷 The filter cake was washed with a ratio of 1:1 and then dried at 110°C to obtain the first membrane layer. Subsequently, the first membrane layer was placed in an argon glove box to immerse it in the ionic liquid for 2 seconds, and then removed and dried at 120°C to control the mass ratio of the ionic liquid to 3% to obtain a quasi-solid electrolyte.

[0264] Example 6

[0265] The difference between this embodiment and Embodiment 1 is that the mixing method of the aramid nanofiber dispersion, metal salt and ligand solution in the preparation method of the quasi-solid electrolyte is different. Specifically, in step S4, no buffer solution is added, and the fourth mixture is directly added to the ligand solution, and then allowed to stand for 24 hours at 30°C in air.

[0266] Example 7

[0267] The difference between this embodiment and Embodiment 2 is that the mixing method of the aramid nanofiber dispersion, metal salt and ligand solution in the preparation method of the quasi-solid electrolyte is different. Specifically, in step S4, the ligand solution is added dropwise to the fourth mixture under stirring conditions, with a dropping rate of 4 mL / min.

[0268] Example 8

[0269] The difference between this embodiment and Example 3 is that the mass ratio of ferrous chloride tetrahydrate and nickel acetate tetrahydrate is 1:1. Specifically, in step S4, 30 mL of aramid nanofiber dispersion, 32 mg of ferrous chloride tetrahydrate and 32 mg of nickel acetate tetrahydrate are mixed.

[0270] Example 9

[0271] The difference between this embodiment and Embodiment 1 is that, in the preparation method of the quasi-solid electrolyte, the volume of the first mixed solution in step S2 is changed from 10 mL to 9.3 mL.

[0272] Example 10

[0273] The difference between this embodiment and Embodiment 1 is that, in the preparation method of the quasi-solid electrolyte, in step S1, the amount of terephthalic acid is changed from 80 mg to 77.5 mg; and in step S4, the amount of nickel acetate tetrahydrate is changed from 80 mg to 77.5 mg.

[0274] Example 11

[0275] The difference between this embodiment and Embodiment 2 is that, in the preparation method of the quasi-solid electrolyte, the volume of the first mixed solution in step S2 is changed from 10 mL to 8.5 mL.

[0276] Example 12

[0277] The difference between this embodiment and Embodiment 2 is that, in the preparation method of the quasi-solid electrolyte, the amount of phenylphosphonic acid in step S1 is changed from 158 mg to 136.4 mg, and the amount of ferric chloride hexahydrate in step S4 is changed from 270 mg to 233.1 mg.

[0278] Example 13

[0279] The difference between this embodiment and Embodiment 3 is that, in the preparation method of the quasi-solid electrolyte, the volume of the first mixed solution in step S2 is changed from 10 mL to 8.6 mL.

[0280] Example 14

[0281] The difference between this embodiment and Embodiment 3 is that, in the preparation method of the quasi-solid electrolyte, the amount of 2-aminoterephthalic acid in step S1 is changed from 70 mg to 60.8 mg, the amount of ferrous chloride tetrahydrate in step S4 is changed from 18 mg to 15.6 mg, and the amount of nickel acetate tetrahydrate is changed from 45 mg to 39.1 mg.

[0282] Comparative Example 1

[0283] The difference between this comparative example and Example 1 is that the nickel-based amorphous metal-organic framework is replaced with a cobalt-based crystalline metal-organic framework. In the preparation method of the quasi-solid electrolyte, 80 mg of terephthalic acid in step S1 is replaced with 120 mg of terephthalic acid; 80 mg of nickel acetate tetrahydrate in step S4 is replaced with 109 mg of cobalt acetate tetrahydrate; and "standing at 30°C in air for 24 h" in step S4 is replaced with "standing at 100°C in air for 24 h".

[0284] II. Testing Methods

[0285] 1. Surface morphology testing of quasi-solid electrolytes

[0286] The quasi-solid electrolytes prepared in Example 1 and Comparative Example 1 were tested and analyzed using a high-resolution transmission electron microscope (HRTEM) to obtain HRTEM images and selected area electron diffraction (SAED) patterns. The instrument model was FEI Talos F200S200kV with a magnification of 100,000.

[0287] 2. Elemental analysis of quasi-solid electrolytes

[0288] The quasi-solid electrolytes prepared in Example 1 and Comparative Example 1 were analyzed using energy dispersive spectroscopy (EDS) to determine the distribution of nitrogen (N), oxygen (O), nickel (Ni), and cobalt (Co) in the quasi-solid electrolytes. The instrument used was a Thermo Scientific Super-X EDS.

[0289] 3. Crystal structure testing of quasi-solid electrolytes

[0290] The quasi-solid electrolytes prepared in Example 1 and Comparative Example 1 were tested using X-ray diffraction (XRE) analysis to obtain XRD patterns. The instrument used was a D8 Discover.

[0291] 4. Testing of the content of each component in quasi-solid electrolytes

[0292] The first film layer (obtained in step S5) prepared in each embodiment and comparative example was tested using a thermogravimetric analyzer (TGA) under an air atmosphere to obtain the mass ratio of para-aramid nanofibers and amorphous metal-organic frameworks. The test temperature was 35℃~1000℃, the heating rate was 10℃ / min, and the instrument model was TGA / DSC 1 / 1600HT. Amorphous metal-organic frameworks typically suffer thermal damage between 400℃ and 600℃, resulting in significant weight loss of the sample. Therefore, the weight loss within the range of 400℃~600℃ was recorded as the mass m1 of the amorphous metal-organic framework, and the residual mass of the sample after the test was recorded as the mass m2 of the para-aramid nanofibers.

[0293] The mass of the quasi-solid electrolyte prepared using the first membrane layer is denoted as m. The formula for calculating the mass m3 of the electrolyte is as follows:

[0294] m3 = m - m1 - m2.

[0295] Finally, the mass percentages of the amorphous metal-organic framework, para-aramid nanofibers, and electrolyte in the quasi-solid electrolyte were calculated based on the values ​​of m, m1, m2, and m3.

[0296] 5. Electrochemical performance testing of quasi-solid electrolytes

[0297] Using the quasi-solid-state electrolytes prepared in each example and comparative example, stainless steel symmetric cells were assembled under nitrogen protection according to the stainless steel electrode-quasi-solid-state electrolyte-stainless steel electrode structure. The stainless steel symmetric cells were then tested as follows:

[0298] (1) Electrochemical impedance spectroscopy (EIS) was performed on the stainless steel symmetrical cell using a BioLogic VMP3 multichannel electrochemical workstation. The test frequency range was 0.1 Hz to 100 kHz and the signal amplitude was 5 mV.

[0299] Next, the ionic conductivity was calculated based on the EIS test results, using the following formula;

[0300] σ=L / (R b ×A),

[0301] Where σ is the ionic conductivity (unit: S / cm), L is the thickness of the quasi-solid electrolyte membrane (unit: cm), and R... b A is the resistance value (unit: Ω), and A is the effective contact area of ​​the stainless steel electrode (unit: cm²). 2 ).

[0302] (2) The capacity retention of the stainless steel symmetrical battery after 200 cycles at 25°C was tested using a multi-channel battery testing system (LAND CT2001A), with the voltage range being 2.8V~4.0V (relative to Li / Li). + The charge / discharge rate is 0.5C.

[0303] III. Analysis of Test Results for Each Embodiment and Comparative Example

[0304] The XRD patterns of the quasi-solid-state electrolytes prepared in Example 1 and Comparative Example 1 are shown below. Figure 1 As shown, the XRD pattern of the quasi-solid electrolyte prepared in Example 1 shows only broadened low-intensity diffraction peaks, indicating that Example 1 successfully prepared an amorphous metal-organic framework. In contrast, the XRD pattern of the quasi-solid electrolyte prepared in Comparative Example 1 shows many sharp and high-intensity diffraction peaks, indicating that Comparative Example 1 prepared a crystalline metal-organic framework.

[0305] TEM images of the quasi-solid-state electrolytes prepared in Example 1 and Comparative Example 1 are shown below. Figures 2 to 3 As shown in the figure. Among them, a is the HRTEM plot and b is the SAED plot. Figure 2 The SAED image shows a diffuse ring shape with no clear diffraction spots, further indicating that the amorphous metal-organic framework prepared in Example 1 is amorphous metal-organic framework. The HRTEM image shows that the amorphous metal-organic framework is uniformly distributed on the surface of para-aramid nanofibers, and the two form a tight interfacial coupling structure. Figure 3 The SAED pattern shows obvious diffraction spots, which further indicates that the material prepared in Comparative Example 1 is a crystalline metal-organic framework (crystalline MOF). The HRTEM image shows that the crystalline metal-organic framework and the para-aramid nanofibers only have partial surface phase contact, and the interfacial compatibility is poor.

[0306] The EDS elemental distribution diagrams of the quasi-solid electrolytes prepared in Example 1 and Comparative Example 1 are shown below. Figures 4 to 5 As shown. You can see that, Figure 4 Amorphous metal-organic frameworks are uniformly distributed on the surface of para-aramid nanofibers, while Figure 5 The distribution of mesocrystalline metal-organic frameworks does not follow a clear pattern.

[0307] The test results of the content of each component in the quasi-solid electrolytes prepared in each example and comparative example are shown in Table 1, and the test results of the electrochemical performance of the quasi-solid electrolytes are shown in Table 2. The thermogravimetric analysis diagram of the quasi-solid electrolyte prepared in Example 1 is shown in Table 2. Figure 6 As shown, the mass of the quasi-solid electrolyte prepared in Example 1 decreases significantly in the temperature range of 400℃ to 600℃. This weight loss is mainly due to thermal damage to the amorphous metal-organic framework. The electrochemical impedance spectroscopy and cycling performance diagrams of the quasi-solid electrolytes prepared in Example 1 and Comparative Example 1 are shown below. Figures 7 to 8 As shown, the quasi-solid electrolyte prepared in Example 1 has significantly lower impedance and better cycling performance after 200 cycles.

[0308] Table 1

[0309]

[0310] Table 2

[0311]

[0312] As shown in Tables 1 and 2, compared with Comparative Example 1, the quasi-solid electrolytes prepared in Examples 1 to 14 have higher ionic conductivity and capacity retention when applied to batteries. This indicates that the present invention significantly reduces the internal impedance of the quasi-solid electrolyte and improves the cycle performance of the battery by using amorphous metal-organic framework as filler and para-aramid nanofibers as polymer skeleton.

[0313] In Example 1, a nickel-based amorphous metal-organic framework was grown in situ on the surface of para-aramid nanofibers using a liquid-liquid interface diffusion method. In Example 2, an iron-based amorphous metal-organic framework was grown in situ on the surface of para-aramid nanofibers using a temperature-controlled method in solvothermal synthesis. In Example 3, an iron-nickel-based amorphous metal-organic framework was grown in situ on the surface of para-aramid nanofibers using a low-temperature, short-reaction-time strategy. The quasi-solid-state electrolytes prepared in Examples 1-3 all exhibited high ionic conductivity and capacity retention, indicating low internal impedance and good interfacial stability. This further demonstrates the good interfacial compatibility between the nickel-based, iron-based, and iron-nickel-based amorphous metal-organic frameworks and the para-aramid nanofibers.

[0314] Example 6 did not employ a liquid-liquid interface diffusion method, resulting in uneven distribution of the nickel-based amorphous metal-organic framework on the surface of the para-aramid nanofibers. This reduced the interfacial coupling strength between the para-aramid nanofibers and the nickel-based amorphous metal-organic framework, hindering ion transport pathways. Consequently, the ionic conductivity and cycling stability of the quasi-solid electrolyte prepared in Example 6 were lower than those in Example 1. Example 7 changed the method of adding the solution, adding the fourth mixture dropwise to the ligand solution. This resulted in excessively large local concentration differences, causing rapid precipitation of metal ions upon contact with the ligands, forming large aggregates. Similarly, this resulted in uneven distribution of the nickel-based amorphous metal-organic framework on the surface of the para-aramid nanofibers, leading to lower ionic conductivity and cycling stability of the quasi-solid electrolyte prepared in Example 7 compared to Example 2. Example 8 changed the mass ratio of ferrous chloride tetrahydrate and nickel acetate tetrahydrate, causing the iron-nickel ratio to be outside the optimal range. This resulted in structural defects in the generated nickel-nickel-based amorphous metal-organic framework, leading to an increased ion transport barrier and reduced interfacial stability. Consequently, the ionic conductivity and cycling stability of the quasi-solid electrolyte prepared in Example 8 were lower than those in Example 3.

[0315] Further, as can be seen from Examples 1-3 and Examples 9-14, when the mass ratio of lithium-sulfur electrolyte, short-cut para-aramid nanofibers and amorphous metal-organic framework in the quasi-solid electrolyte is adjusted to a suitable range according to the type of metal, the prepared quasi-solid electrolyte has high ionic conductivity and capacity retention.

[0316] Comparative Example 1 uses a crystalline metal-organic framework as a filler. The rigid lattice in the crystalline metal-organic framework has poor interfacial compatibility with the comparative aramid nanofibers, resulting in a high ion transport energy barrier. Therefore, the quasi-solid electrolyte prepared using it has high internal impedance and poor interfacial stability, which in turn leads to low ionic conductivity and poor cycle performance when the quasi-solid electrolyte is applied to the battery.

[0317] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A quasi-solid-state electrolyte, characterized in that, It includes an electrolyte, para-aramid nanofibers, and an amorphous metal-organic framework; wherein the amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

2. The quasi-solid-state electrolyte according to claim 1, characterized in that, The mass ratio of the electrolyte, the para-aramid nanofibers, and the amorphous metal-organic framework is 1:(2.7~30.0):(12.2~69.0).

3. The quasi-solid-state electrolyte according to claim 1 or 2, characterized in that, At least one of the following conditions must be met: (1) The electrolyte includes at least one of lithium-sulfur electrolyte, lithium-ion secondary electrolyte, and ionic liquid, and the electrolyte contains lithium salt; (2) The metal elements in the amorphous metal-organic framework include at least one of nickel and iron.

4. A method for preparing a quasi-solid-state electrolyte, characterized in that, The steps include the following: The ligand and the first solvent phase are mixed to obtain a ligand solution; Para-aramid fibers, an alkali agent, and a second solvent are mixed to obtain a first mixture. Subsequently, the first mixture is mixed with a protic solvent to obtain a second mixture. The second mixture is subjected to a first solid-liquid separation and solvent replacement treatment in sequence to obtain an aramid nanofiber dispersion, wherein the aramid nanofiber dispersion contains para-aramid nanofibers; The aramid nanofiber dispersion, the metal salt, and the ligand solution are mixed to obtain a third mixture; The third mixture is subjected to a second solid-liquid separation to obtain a first membrane layer. Subsequently, the first membrane layer is wetted with electrolyte and dried to obtain a quasi-solid electrolyte. The quasi-solid electrolyte comprises an electrolyte, para-aramid nanofibers, and an amorphous metal-organic framework; the amorphous metal-organic framework is located on the surface of the para-aramid nanofibers.

5. The method for preparing the quasi-solid electrolyte according to claim 4, characterized in that, At least one of the following conditions must be met: (1) The ligand comprises at least one of terephthalic acid, phenylphosphonic acid, and 2-aminoterephthalic acid; (2) The alkaline agent comprises at least one of potassium hydroxide, sodium hydroxide, potassium tert-butoxide, and sodium tert-butoxide; (3) The metal salt comprises at least one of nickel acetate tetrahydrate, ferric chloride hexahydrate, and ferrous chloride tetrahydrate; (4) The mass ratio of the para-aramid nanofiber, the ligand, and the metal salt is 1:(3.0~9.3):(2.7~15.9); (5) The mass ratio of the para-aramid fiber to the alkali agent is 1:(1.2~1.8). (6) The first solvent contains at least one of N,N-dimethylformamide, acetonitrile, and ethanol; (7) The second solvent comprises at least one of dimethyl sulfoxide, N,N-dimethylformamide, and N,N-dimethylacetamide; (8) The protic solvent comprises at least one of water, ethanol, diethyl ether, acetone, methanol, and isopropanol; (9) The aramid nanofiber dispersion comprises a mixture of N,N-dimethylformamide and acetonitrile; (10) The aramid nanofiber dispersion contains a mixture of N,N-dimethylformamide and acetonitrile; the volume ratio of N,N-dimethylformamide to acetonitrile is 1: (1.9~2.1).

6. The method for preparing the quasi-solid electrolyte according to claim 4 or 5, characterized in that, The method for mixing the aramid nanofiber dispersion, the metal salt, and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture; adding the ligand solution, the buffer solution, and the fourth mixture layer by layer from bottom to top into a container; and then allowing it to stand; and the preparation method of the quasi-solid electrolyte satisfies at least one of the following conditions: (1) The ligand is terephthalic acid; (2) The metal salt is nickel acetate tetrahydrate; (3) The mass ratio of the para-aramid nanofiber, the ligand, and the metal salt is 1:(3.9~4.3):(3.9~4.3). (4) The first solvent is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (1.9~2.1):1; (5) The buffer solution is a mixed solution of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (0.9~1.1):(0.9~1.1). (6) The volume ratio of the ligand solution, the buffer solution and the fourth mixture is (2.5~3.5):(1.5~2.5):(2.5~3.5).

7. The method for preparing the quasi-solid electrolyte according to claim 4 or 5, characterized in that, The method for mixing the aramid nanofiber dispersion, the metal salt, and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture, adding the fourth mixture to the ligand solution, and allowing it to stand; and the preparation method of the quasi-solid electrolyte satisfies at least one of the following conditions: (1) The ligand is phenylphosphonic acid; (2) The metal salt is ferric chloride hexahydrate; (3) The mass ratio of the para-aramid nanofiber, the ligand, and the metal salt is 1:(6.8~9.3):(11.7~15.9). (4) The first solvent is ethanol; (5) The volume ratio of the ligand solution to the fourth mixture is (0.9~1.1):(0.9~1.1).

8. The method for preparing the quasi-solid electrolyte according to claim 4 or 5, characterized in that, The method for mixing the aramid nanofiber dispersion, the metal salt, and the ligand solution includes the following steps: mixing the aramid nanofiber dispersion and the metal salt to obtain a fourth mixture; mixing the fourth mixture and the ligand solution to carry out a reaction; and the preparation method of the quasi-solid electrolyte satisfies at least one of the following conditions: (1) The ligand is 2-aminoterephthalic acid; (2) The metal salts are ferrous chloride tetrahydrate and nickel acetate tetrahydrate; (3) The metal salt is ferrous chloride tetrahydrate and nickel acetate tetrahydrate, and the mass ratio of ferrous chloride tetrahydrate to nickel acetate tetrahydrate is 1: (2.4~2.6). (4) The mass ratio of the para-aramid nanofiber, the ligand, and the metal salt is 1:(3.0~4.1):(2.7~3.7). (5) The first solvent is a mixture of N,N-dimethylformamide and acetonitrile, and the volume ratio of N,N-dimethylformamide to acetonitrile is (1.9~2.1):1; (6) The volume ratio of the ligand solution to the fourth mixture is (0.9~1.1):(0.9~1.1).

9. The method for preparing the quasi-solid electrolyte according to claim 4 or 5, characterized in that, At least one of the following conditions must be met: (1) The electrolyte comprises at least one of lithium-sulfur electrolyte, lithium-ion secondary electrolyte, and ionic liquid, and the electrolyte contains lithium salt; (2) The length of the para-aramid fiber is 0.6 μm to 1.8 μm; the aspect ratio of the para-aramid fiber is (10~45):1; (3) In the quasi-solid electrolyte, the mass percentage of the electrolyte is 1% to 5%.

10. A battery, characterized in that, The battery comprises a positive electrode material, a negative electrode material, and an electrolyte, wherein the electrolyte is a quasi-solid-state electrolyte as described in any one of claims 1 to 3, or a quasi-solid-state electrolyte prepared by the preparation method as described in any one of claims 4 to 9.

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