Solid-state battery cell and method of manufacturing the same, battery device, power consuming device, and energy storage device

Abstract

The application relates to a solid-state battery monomer and a preparation method thereof, a battery device, a power utilization device and an energy storage device. The preparation method of the solid-state battery monomer comprises the following steps: performing impurity removal treatment on a metal organic framework material to obtain a modified metal organic framework material; sequentially performing ball milling treatment and heat treatment on a sulfide electrolyte precursor and the modified metal organic framework material to obtain a composite solid-state electrolyte; the rotating speed of the ball milling treatment is 100 rpm-200 rpm, and the temperature of the heat treatment is 260 DEG C-280 DEG C; performing first pressing treatment on the composite solid-state electrolyte to obtain a composite solid-state electrolyte film; stacking a positive electrode, the composite solid-state electrolyte film and a negative electrode, the composite solid-state electrolyte film is arranged between the positive electrode and the negative electrode, and second pressing treatment is performed to obtain a solid-state battery. The preparation method of the solid-state battery monomer can effectively improve the rate performance and cycle life of the solid-state battery monomer.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to solid-state battery cells and their preparation methods, battery devices, power-consuming devices, and energy storage devices. Background Technology

[0002] With the rapid development of the electric vehicle and energy storage markets, the requirements for battery energy density, safety, and cycle life are constantly increasing. Solid-state batteries use solid electrolytes to replace traditional liquid electrolytes, fundamentally solving the safety hazards of liquid batteries. However, the rate performance and cycle life of traditional solid-state batteries still need further improvement. Summary of the Invention

[0003] Based on this, this application provides a solid-state battery cell that can effectively improve rate performance and cycle life, as well as its preparation method, battery device, power consumption device, and energy storage device.

[0004] The technical solution to the above-mentioned technical problems in this application is as follows.

[0005] The first aspect of this application provides a method for preparing a solid-state battery cell, comprising the following steps:

[0006] Modified metal-organic framework materials are obtained by removing impurities from metal-organic framework materials.

[0007] The sulfide electrolyte precursor and the modified metal-organic framework material are mixed and then subjected to ball milling and heat treatment in sequence to obtain a composite solid electrolyte; the ball milling speed is 100 rpm to 200 rpm and the heat treatment temperature is 260℃ to 280℃.

[0008] The composite solid electrolyte is subjected to a first pressing process to obtain a composite solid electrolyte membrane.

[0009] A positive electrode, the composite solid electrolyte membrane, and a negative electrode are stacked together, with the composite solid electrolyte membrane disposed between the positive electrode and the negative electrode. After a second pressing process, a solid-state battery is obtained.

[0010] The above-mentioned method for preparing solid-state battery cells involves first removing impurities from the metal-organic framework (MOF) material, such as residual solvents and coordination water, within the MOF channels. Then, a sulfide electrolyte precursor and a modified MOF material are mixed and ball-milled to promote the complete entry of the sulfide electrolyte precursor into the pores of the modified MOF material. Following heat treatment, the sulfide electrolyte precursor generates sulfide electrolyte in situ within the pores of the modified MOF material, forming a good interfacial contact between the sulfide electrolyte and the modified MOF material, effectively reducing interfacial impedance. Simultaneously, the modified MOF material possesses nanopores, which, through spatial confinement effects, control the nucleation and growth of the sulfide electrolyte, achieving uniform dispersion of the sulfide electrolyte at the nanoscale. By controlling the ball milling speed and heat treatment temperature, the integrity of the modified MOF material's framework is effectively preserved, allowing it to serve as a three-dimensional reinforcing phase for the sulfide electrolyte. These multi-faceted interactions effectively improve the ionic conductivity and mechanical properties of the composite solid-state electrolyte. The composite solid electrolyte is processed into a composite solid electrolyte membrane through a first pressing process, and then processed with the positive and negative electrodes through a second pressing process to obtain a solid battery, which can effectively improve the rate performance and cycle life of the solid battery cell. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application and to more completely understand this application and its beneficial effects, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a schematic flowchart of a method for preparing a solid-state battery cell according to one embodiment. Detailed Implementation

[0013] The present application will be further described in detail below with reference to the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the disclosure of the present application more thorough and comprehensive.

[0014] It should also be understood that this application can be implemented in many different forms and is not limited to the embodiments and examples described herein. Those skilled in the art can make various alterations or modifications without departing from the spirit of this application, and the resulting equivalent forms also fall within the protection scope of this application. For example, features described or illustrated as part of one embodiment can be combined in a suitable manner in another embodiment to produce new embodiments. Furthermore, numerous specific details are set forth in the following description to provide a fuller understanding of this application; it should be understood that this application can be implemented without one or more of these details.

[0015] 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 belongs. The terminology used herein in the specification of this application is for descriptive purposes only and is not intended to be limiting of the application.

[0016] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0017] In this application, the terms "multiple", "various", "multiple times", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0018] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0019] In this document, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0020] In this application, terms such as "further," "even further," and "particularly" are used to describe purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0021] In this application, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0022] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0023] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed herein should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include numerical interval types such as percentage intervals, ratio intervals, and proportion intervals.

[0024] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0025] In this application, the term "room temperature" or "normal temperature" generally refers to 4℃~35℃, including but not limited to 4℃, 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃, and 35℃; in some examples, it can be any two of these point values ​​as endpoints, the same applies below; for example, 20℃±5℃. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10℃~30℃. Optionally, "room temperature" or "normal temperature" refers to 20℃~30℃.

[0026] In this application, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0027] The mass or weight of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship of mass or weight between the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass or weight mentioned in the embodiments of this application can be units known in the chemical industry, such as μg, mg, g, and kg.

[0028] Studies have found that controlling the particle size and dispersibility of sulfide solid electrolytes is difficult. During preparation and post-processing, they are prone to agglomeration, forming micron-sized or even larger aggregates. This not only reduces the specific surface area and affects contact with the electrode, but also creates stress concentration points in the composite material, leading to a decline in mechanical properties. Polymer composites can solve the agglomeration problem between sulfide solid electrolytes to some extent, but there are significant chemical and physical incompatibilities between sulfide solid electrolytes and polymers: sulfides are inorganic ionic conductors, while polymers are organic materials. The significant difference in their surface properties leads to the formation of a high-resistivity layer at the interface, which not only increases the internal resistance of the battery but also causes uneven current distribution at the interface, accelerating interface degradation. Furthermore, the ionic conductivity of polymers is much lower than that of sulfides, requiring a high sulfide loading (>60wt%) to form an effective conductive network. However, a high loading can cause the composite material to become brittle, creating a vicious cycle.

[0029] The study also found that mixing sulfide electrolyte products with metal-organic framework materials can lead to problems such as severe sulfide particle agglomeration, uneven particle size distribution, high interfacial resistance with the polymer matrix, high mechanical brittleness of pure sulfide electrolytes, and difficulty in processing and molding.

[0030] See Figure 1 This application provides a method for preparing a solid-state battery cell, comprising the following steps:

[0031] Step S100: Remove impurities from the metal-organic framework material to obtain the modified metal-organic framework material;

[0032] Step S200: The sulfide electrolyte precursor and the modified metal-organic framework material are mixed and then subjected to ball milling and heat treatment in sequence to obtain a composite solid electrolyte; the ball milling speed is 100 rpm to 200 rpm and the heat treatment temperature is 260℃ to 280℃.

[0033] First, the metal-organic framework (MOF) material is purified to remove residual solvents and coordination water from the pores. Then, a sulfide electrolyte precursor is mixed with the modified MOF and ball-milled to promote the full penetration of the sulfide electrolyte precursor into the pores. Heat treatment at a specific temperature allows the sulfide electrolyte precursor to generate sulfide electrolytes in situ within the pores. The sulfide electrolytes are dispersed in nanocrystals or near-amorphous forms within the MOF pores and on the pore wall surface. The metal clusters and organic ligands in the MOF framework form chemical bonds or strong interactions with the in-situ generated sulfides, enabling the sulfide electrolytes to... The modified metal-organic framework (MOF) forms a tight atomic / molecular contact with the metal-organic framework, eliminating macroscopic phase interfaces and constructing an integrated composite structure without macroscopic interfaces, significantly reducing interfacial impedance. Utilizing the regular nanopores of MOF as a "nanoreactor," the nucleation and growth of sulfide electrolytes are controlled through spatial confinement effects, achieving uniform dispersion and controllable growth of sulfide electrolytes at the nanoscale, effectively suppressing particle aggregation. By controlling the ball milling speed and heat treatment temperature, the integrity of the modified metal-organic framework is effectively preserved, serving as a three-dimensional reinforcing phase for the sulfide electrolyte. Through multiple interactions, the ionic conductivity, mechanical properties, and processing performance of the composite solid electrolyte can be effectively improved.

[0034] The bifunctional MOF framework serves both as a reaction vessel to control sulfide growth and as a three-dimensional reinforcing phase for the final composite solid electrolyte, improving the mechanical strength of the composite solid electrolyte. Meanwhile, the organic ligands endow the composite solid electrolyte with a certain degree of flexibility. The pore walls of the MOF can also provide additional transport paths for lithium ions, forming a synergistic effect with the bulk conduction of sulfides.

[0035] In some examples, in step S100, the pore size of the modified metal-organic framework material is 1.2 nm to 3 nm. It is understood that the pore size of the modified metal-organic framework material includes, but is not limited to, 1.2 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, 1.8 nm, 1.9 nm, 2 nm, 2.1 nm, 2.2 nm, 2.3 nm, 2.4 nm, 2.5 nm, 2.6 nm, 2.7 nm, 2.8 nm, 2.9 nm, and 3 nm.

[0036] In some examples, in step S100, the metal-organic framework material includes a zirconium-based metal-organic framework material. Optionally, the zirconium-based metal-organic framework material includes at least one of MOF-808, NU-1000, and UiO-66. Accordingly, the modified metal-organic framework material includes a modified zirconium-based metal-organic framework material.

[0037] Understandably, in some of these examples, the crystallinity of the modified metal-organic framework material is >90%; it needs to be processed and stored in an anhydrous and oxygen-free environment, such as by transferring it to an argon glove box (H2O <1ppm, O2 <1ppm).

[0038] It is understandable that by controlling the heat treatment temperature, it is possible to ensure that the sulfide electrolyte precursor reacts fully to form the sulfide electrolyte, while also maintaining the structural integrity of the MOF framework and preventing particle coarsening. Furthermore, it is understood that excessively high heat treatment temperatures will damage the structural integrity of the MOF framework and also lead to particle coarsening. It is also understood that the heat treatment temperature includes, but is not limited to, 260℃, 261℃, 262℃, 263℃, 264℃, 265℃, 266℃, 267℃, 268℃, 269℃, 270℃, 271℃, 272℃, 273℃, 274℃, 275℃, 276℃, 277℃, 278℃, 279℃, and 280℃; in some examples, any two of these values ​​can be used as endpoints within a range, and the same applies below. Optionally, the heat treatment temperature is 265℃~275℃.

[0039] In some examples, the heat treatment time in step S200 is 2 h to 4 h. It is understood that the heat treatment time includes, but is not limited to, 2 h, 2.1 h, 2.2 h, 2.3 h, 2.4 h, 2.5 h, 2.6 h, 2.7 h, 2.8 h, 2.9 h, 3 h, 3.1 h, 3.2 h, 3.3 h, 3.4 h, 3.5 h, 3.6 h, 3.7 h, 3.8 h, 3.9 h, and 4 h. Optionally, the heat treatment time is 2.5 h to 3.5 h.

[0040] In some of these examples, in step S200, the heat treatment is performed under an inert atmosphere. Optionally, the inert atmosphere includes, but is not limited to, at least one of argon and nitrogen.

[0041] In some examples, in step S200, the heating rate to the heat treatment temperature is 1.5℃ / min to 3℃ / min. This can be understood as heating from room temperature to the heat treatment temperature; further, the heating rate to the heat treatment temperature includes, but is not limited to, 1.5℃ / min, 1.6℃ / min, 1.7℃ / min, 1.8℃ / min, 1.9℃ / min, 2℃ / min, 2.1℃ / min, 2.2℃ / min, 2.3℃ / min, 2.4℃ / min, 2.5℃ / min, 2.6℃ / min, 2.7℃ / min, 2.8℃ / min, 2.9℃ / min, and 3℃ / min. By controlling the heating rate, local overheating can be avoided, the grain growth rate can be controlled, and the uniform dispersion and controllable growth of the sulfide electrolyte can be further promoted, thereby improving the ionic conductivity, mechanical properties, and processing performance of the composite solid electrolyte.

[0042] It is understandable that controlling the ball milling speed can effectively reduce the impact on the integrity of the modified metal-organic framework (MOF). Furthermore, it is understood that higher ball milling speeds can lead to the breakage of MOF coordination bonds, the collapse of the three-dimensional ordered pore structure, and a significant decrease in specific surface area and pore volume. Pore collapse renders the originally orderly confined space disordered, depriving sulfide nucleation and growth of nanoscale spatial constraints, resulting in a wider particle size distribution. Damage to the MOF framework also weakens its mechanical support role as a three-dimensional reinforcing phase, reducing the overall mechanical properties of the composite electrolyte. It is also understood that ball milling speeds include, but are not limited to, 100 rpm, 110 rpm, 120 rpm, 130 rpm, 140 rpm, 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm, and 200 rpm.

[0043] In some examples, the ball milling process in step S200 takes 1 to 2 hours. It is understood that the ball milling time includes, but is not limited to, 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, and 2 hours.

[0044] In some examples, in step S200, the mixing is carried out under an inert atmosphere. Optionally, the inert atmosphere includes, but is not limited to, at least one of argon and nitrogen.

[0045] It is understood that in some of these examples, the impurity removal process in step S200 includes removing solvent from the pores of the metal-organic framework material, and further, the solvent includes at least one of an organic solvent and water.

[0046] In some of these examples, step S200 includes vacuum purification of the metal-organic framework material at 120°C to 200°C under vacuum conditions.

[0047] Metal-organic framework (MOF) materials are activated under specific conditions to remove guest molecules (residual solvents and coordination water) from the pores, resulting in a significant recovery of the MOF's specific surface area. It is understood that vacuum purification temperatures include, but are not limited to, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, and 200℃.

[0048] In some examples, in step S200, the mass ratio of the sulfide electrolyte precursor to the modified metal-organic framework material is 1.5 to 3:1. It is understood that the mass ratio of the sulfide electrolyte precursor to the modified metal-organic framework material includes, but is not limited to, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, and 3:1.

[0049] By controlling the mass ratio of sulfide electrolyte precursor to modified metal-organic framework material, both the high sulfide content provides high ionic conductivity, and the sufficient MOF framework provides structural support and long-term stability.

[0050] In some examples, in step S200, the sulfide electrolyte precursor includes lithium sulfide and phosphorus pentasulfide. It can be understood that using lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) as the sulfide electrolyte precursor generates Li3PS4 and Li4P2S7 mesophases, which, after rearrangement and interconversion, ultimately form Li7P3S. 11 Sulfide electrolytes have high ionic conductivity, reaching 10 at room temperature. -2 The reaction rate was at the S / cm level. A solid-state reaction of Li₂S and P₂S₅ to produce Li₇P₃S was achieved at a relatively low temperature of 260℃~280℃. 11 It can effectively avoid particle growth and MOF framework decomposition caused by high-temperature sintering, has good mechanical ductility, low grain boundary impedance, and good electrochemical stability.

[0051] Optionally, the molar ratio of lithium sulfide to phosphorus pentasulfide is 2.2~2.6:1. It is understood that the molar ratio of lithium sulfide to phosphorus pentasulfide includes, but is not limited to, 2.2:1, 2.3:1, 2.4:1, 2.5:1, and 2.6:1. Optionally, the molar ratio of lithium sulfide to phosphorus pentasulfide is 2.3~2.5:1. Further, the molar ratio of lithium sulfide to phosphorus pentasulfide is 2.3~2.4:1. By controlling the molar ratio of lithium sulfide to phosphorus pentasulfide, it is beneficial to form Li7P3S. 11 The target phase is suppressed to prevent the presence of low-conductivity phases such as Li3PS4 or Li4P2S7; if necessary, a slight enrichment of lithium can be applied to stabilize the high-conductivity phase.

[0052] Optionally, the purity of lithium sulfide and phosphorus pentasulfide shall be ≥99% independently, the moisture content shall be ≤50 ppm, and the particle size D50 (median volume diameter) shall be 10 μm to 50 μm. Li2S is hygroscopic, and P2S5 is easily hydrolyzed to generate H2S and phosphoric acid; vacuum drying shall be performed before use to ensure that the moisture content is <50 ppm.

[0053] In some examples, in step S200, during the mixing process, lithium sulfide and phosphorus pentasulfide are first mixed to obtain a mixed precursor; then the mixed precursor is mixed with a modified metal-organic framework material.

[0054] Optionally, lithium sulfide and phosphorus pentasulfide are stirred and mixed at a speed of 100 rpm to 300 rpm for 1 h to 3 h.

[0055] In some of these examples, no solvent is added during step S200, during mixing. It can be understood that a solid-phase reaction is achieved during heat treatment.

[0056] In other examples, solvent-assisted infiltration (SALI) can be used: a sulfide electrolyte precursor and a solvent are mixed to form a suspension, a modified metal-organic framework material is added and stirred; then the solvent is removed.

[0057] It is understood that the solvent serves only for physical transport and wetting, and does not chemically react with the precursor. Optionally, the solvent includes at least one of fluoroethers (such as HFE-7100) and perfluorocarbon solvents. Optionally, the volume ratio of the solvent to the mass of the modified metal-organic framework material is 1 mL / g to 2 mL / g.

[0058] In some of these examples, step S200, during mixing, also includes the addition of lithium halide.

[0059] The addition of lithium halides during heat treatment can act as a grain boundary conductor, defect passivator, and densification promoter, reducing interfacial impedance and increasing densification. During densification pressing, it can promote plastic deformation and interfacial contact between particles, thereby increasing the relative density, ionic conductivity, and grain boundary transport of the composite solid electrolyte.

[0060] Optionally, the lithium halide includes at least one of lithium iodide (LiI) and lithium bromide (LiBr). Optionally, the mass of lithium halide is 0.5 wt% to 2 wt% of the total mass of the sulfide electrolyte precursor. It is understood that the percentage of lithium halide mass to the total mass of the sulfide electrolyte precursor includes, but is not limited to, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, and 2 wt%. Optionally, the mass of lithium halide is 1 wt% to 1.5 wt% of the total mass of the sulfide electrolyte precursor. By controlling the amount of lithium halide added, interfacial side reactions are controlled while improving the ionic conductivity of the composite solid electrolyte and improving grain boundary transport.

[0061] In some examples, step S200 involves heat treatment in a quartz tube or stainless steel reactor; optionally, the reactor contains an H2S absorbent; optionally, the H2S absorbent includes zinc oxide. In some examples, step S200 is carried out in an environment with a dew point ≤ -40°C or H2O / O2 ≤ 50ppm. This ensures process controllability and safety.

[0062] Step S300: The composite solid electrolyte is subjected to a first pressing process to obtain a composite solid electrolyte membrane.

[0063] In some of these examples, in step S300, the first pressing process is cold pressing.

[0064] Optionally, the cold pressing temperature is 4℃~30℃. Optionally, the cold pressing pressure is 300 MPa~500 MPa. Optionally, the cold pressing time is 2 min~5 min.

[0065] It can be understood that cold pressing refers to a molding process in which unidirectional or bidirectional pressure is applied to materials at room temperature, causing the material particles to undergo plastic deformation, compactly pack together, and form a green body with a certain shape. Furthermore, it can be understood that the cold pressing temperature includes, but is not limited to, 4℃, 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, and 30℃; the cold pressing pressure includes, but is not limited to, 300 MPa, 310 MPa, 320 MPa, 330 MPa, 340 MPa, 350 MPa, 360 MPa, 370 MPa, 380 MPa, 390 MPa, 400 MPa, 410 MPa, 420 MPa, 430 MPa, 440 MPa, 450 MPa, 460 MPa, 470 MPa, 480 MPa, 490 MPa, and 500 MPa; and the cold pressing time includes, but is not limited to, 2... min, 3 min, 4 min, 5 min.

[0066] In some examples, after the first pressing process, step S300 further includes: subjecting the billet obtained from the first pressing process to a third pressing process; the third pressing process is selected from warm pressing or cold isostatic pressing (CIP).

[0067] It can be understood that thermostatic pressing refers to a process of applying pressure to a material within a range above room temperature but below its melting point / phase transition temperature to achieve molding. Its core principle is to utilize temperature to increase the material's plasticity and reduce the pressure required for molding. Cold isostatic pressing, on the other hand, refers to a process of applying uniform static pressure to a material at room temperature using a high-pressure medium (such as hydraulic oil, water, or glycerin) to achieve material densification. It is a type of isostatic pressing (distinct from hot isostatic pressing).

[0068] The composite solid electrolyte is subjected to a first pressing process, and then the preform obtained from the first pressing process is subjected to a third pressing process to ensure high-density molding while maintaining the integrity of the MOF skeleton.

[0069] Optionally, the temperature for thermo-pressure testing is 70℃~120℃. Optionally, the pressure for thermo-pressure testing is 100 MPa~300 MPa. Optionally, the time for thermo-pressure testing is 10 min~20 min.

[0070] It is understood that the temperature of the thermo-pressure test includes, but is not limited to, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, and 120℃; the pressure of the thermo-pressure test includes, but is not limited to, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, 260 MPa, 270 MPa, 280 MPa, 290 MPa, and 300 MPa; and the time of the thermo-pressure test includes, but is not limited to, 10 min, 12 min, 14 min, 16 min, 18 min, and 20 min.

[0071] Optionally, the temperature for cold isostatic pressing is 4℃~30℃. Optionally, the pressure for cold isostatic pressing is 200 MPa~400 MPa. It is understood that the temperature for cold isostatic pressing includes, but is not limited to, 4℃, 5℃, 6℃, 7℃, 8℃, 9℃, 10℃, 11℃, 12℃, 13℃, 14℃, 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, and 30℃; and the pressure for cold isostatic pressing includes, but is not limited to, 200 MPa, 210 MPa, 220 MPa, 230 MPa, 240 MPa, 250 MPa, 260 MPa, 270 MPa, 280 MPa, 290 MPa, 300 MPa, 310 MPa, 320 MPa, 330 MPa, 340 MPa, 350 MPa, 360 MPa, 370 MPa, 380 MPa, 390 MPa, and 400 MPa.

[0072] By controlling the first pressing process to be cold pressing, and controlling the temperature and pressure of the cold pressing, the composite solid electrolyte is formed into a film (green body), while ensuring the integrity of the modified metal-organic framework material of the composite solid electrolyte in the green body. Optionally, the relative density of the green body obtained by the first pressing process is about 85%~90%. The green body obtained by the first pressing process is then subjected to a third pressing process, which is controlled to be selected from warm pressing or cold isostatic pressing, to eliminate the porosity between powder particles and ensure high-density molding while maintaining the integrity of the MOF framework. Optionally, the relative density of the composite solid electrolyte film obtained by the third pressing process is ≥95%. It can be understood that relative density refers to the ratio of the actual density of the composite solid electrolyte film to the theoretical maximum density of the composite solid electrolyte film.

[0073] Step S400: The positive electrode, the composite solid electrolyte membrane, and the negative electrode are stacked together, with the composite solid electrolyte membrane placed between the positive and negative electrodes. After a second pressing process, a solid-state battery is obtained.

[0074] The composite solid electrolyte obtained in step S300 is subjected to a first pressing process to obtain a composite solid electrolyte membrane, and then subjected to a second pressing process with the positive and negative electrodes to obtain a solid battery. This can effectively improve the interfacial stability between the composite solid electrolyte membrane and the positive and negative electrodes, effectively improve the rate performance and cycle life of the solid battery cell, and effectively improve the first-cycle coulombic efficiency and high-temperature storage performance of the solid battery cell.

[0075] In some examples, in step S400, the pressure of the second pressing process is 10 MPa to 20 MPa. It can be understood that the pressure of the second pressing process includes, but is not limited to, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, and 20 MPa.

[0076] In some examples, step S400, during stacking, further includes: setting an interface layer between the positive electrode and the composite solid electrolyte membrane, the interface layer comprising Li3PS4.

[0077] One embodiment of this application provides a solid-state battery cell, which is prepared using the above-described method for preparing solid-state battery cells.

[0078] In some of these examples, the solid-state battery cell includes a positive electrode, a composite solid electrolyte membrane, and a negative electrode stacked together, with the composite solid electrolyte membrane disposed between the positive and negative electrodes.

[0079] In some of these examples, the thickness of the composite solid electrolyte membrane in the solid-state battery cell is 60 μm to 300 μm.

[0080] In some examples, the porosity of the composite solid electrolyte membrane in the solid-state battery cell is ≤5%. It is understood that the porosity of the composite solid electrolyte membrane is 1% to 5%. It is understood that the porosity of the composite solid electrolyte membrane includes, but is not limited to, 1%, 2%, 3%, 4%, and 5%.

[0081] In some of these examples, the relative density of the composite solid electrolyte membrane in the solid-state battery cell is ≥85%; optionally, the relative density of the composite solid electrolyte membrane is 85%~98%; it is understood that the relative density of the composite solid electrolyte membrane includes, but is not limited to, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, and 98%.

[0082] In some of these examples, the relative density of the composite solid electrolyte membrane in the solid-state battery cell is ≥95%. Optionally, the relative density of the composite solid electrolyte membrane is 95%~98%.

[0083] In some examples, in the solid-state battery cell, the positive electrode active material includes at least one of nickel-based ternary materials and lithium iron phosphate materials. Optionally, the nickel-based ternary material is a high-nickel ternary material; optionally, the high-nickel ternary material is NCM811; optionally, the positive electrode active material includes a core and a coating layer disposed on the surface of the core, wherein the core is a high-nickel ternary material and the shell is LiNbO3. Optionally, the thickness of the coating layer is 3 nm to 5 nm. The coating layer can reduce interfacial side reactions.

[0084] In some of these examples, the negative electrode active material in a solid-state battery cell includes at least one of lithium, graphite, and silicon.

[0085] In some of these examples, the solid-state battery cells operate at a voltage of 2.8 V to 4.4 V and a temperature of 25°C to 60°C; they support charge and discharge rates of 0.2C to 5C.

[0086] The solid-state battery cells provided in this application can be applied to, but are not limited to, electrical devices such as vehicles, ships, and aircraft, as well as energy storage devices with long-term energy storage such as 4 hours and 8 hours. Using the solid-state battery cells and battery devices disclosed in this application to construct power systems for electrical devices or energy storage devices is beneficial for improving system rate performance and cycle life, while also meeting the application requirements of high-capacity batteries.

[0087] One embodiment of this application provides a battery device including the above-mentioned solid-state battery cell, and the battery device includes at least one of a battery module and a battery pack.

[0088] One embodiment of this application provides an electrical device, including the aforementioned solid-state battery cell or the aforementioned battery device. This electrical device may be, but is not limited to, a mobile phone, tablet, laptop, electric toy, power tool, electric vehicle, electric car, etc. The electric toy may include stationary or mobile electric toys, such as game consoles, electric car toys, electric boat toys, and electric airplane toys, etc.

[0089] One embodiment of this application provides an energy storage device, including the aforementioned solid-state battery cell or the aforementioned battery device. It is understood that the energy storage device includes, but is not limited to, energy storage containers, energy storage cabinets, energy storage power stations, energy storage battery packs, or portable energy storage systems, suitable for long-term energy storage, and dedicated energy storage units adapted to long-term energy storage such as 4 hours or 8 hours.

[0090] The present application will be described in further detail below with reference to specific embodiments, but the embodiments of the present application are not limited thereto.

[0091] The following are some of the materials used in the various embodiments and comparative examples:

[0092] MOF-808, with the chemical formula Zr6O4(OH)4(BTC)6, where BTC is 1,3,5-benzenetricarboxylate, has spherical pores of 1.8 nm to 2.0 nm and a specific surface area greater than 1500 m². 2 / g, crystallinity greater than 90%. NU-1000, chemical formula Zr6(μ3-O)4(μ3-OH)4(OH)4(H2O)4(TBAPy)2, where TBAPy is 1,3,6,8-tetra(terebenzoic acid)pyrene, has a hierarchical pore structure of 1.2 nm and 3.0 nm. UiO-66 is prepared through defect engineering or post-processing modification to introduce defect sites to increase precursor accessibility. Upon receipt, MOF materials are immediately transferred to an argon glove box for storage, with the water and oxygen content in the glove box controlled below 1 ppm.

[0093] Lithium sulfide is a battery-grade product with a purity of not less than 99.5% and a particle size D50 of 10 μm to 50 μm. Phosphorus pentasulfide is a sublimated purified product with a purity of not less than 99.9%. Lithium iodide or lithium bromide is an anhydrous product with a purity of not less than 99%. Because the above-mentioned sulfide precursors and accelerators are extremely sensitive to moisture, they must be repackaged and sealed in a glove box after opening. Before use, they should be vacuum dried at 80℃ and 60℃ for 2 hours and 1 hour respectively to ensure a moisture content of less than 50 ppm.

[0094] Example 1

[0095] (1) Activation (purification) treatment of carrier (MOF): Place MOF powder (MOF-808) in a tube furnace and connect it to a vacuum system. Activation procedure: Evacuate to <10Pa at room temperature; heat to 120℃ at 2℃min and hold for 2 hours; continue to heat to 180℃ and hold for 8 hours; allow to cool naturally to room temperature under vacuum; purge with high-purity argon and quickly transfer to a glove box.

[0096] (2) Grind Li2S, P2S5 and LiI by hand in an agate mortar for 10 minutes to initially mix them; then transfer them to a planetary ball mill and use zirconia balls (ball-to-material ratio 3:1) to ball mill at 150 rpm for 1 hour to obtain a precursor mixed powder with D50 < 1 μm; the molar ratio of Li2S to P2S5 is 2.33:1, and the mass of LiI is 1.2 wt% of the total mass of the sulfide electrolyte precursors Li2S and P2S5.

[0097] (3) The MOF powder activated in step (1) and the precursor powder prepared in step (2) are mixed in a mass ratio of 30:70 and processed in a closed low-energy ball mill at 100 rpm for 30 minutes.

[0098] (4) Heat treatment: In a glove box, the MOF powder of the loaded precursor obtained in step (3) was loaded into a quartz tube reactor. 0.5g of zinc oxide powder (separated by porous ceramic sheets) was placed at the bottom of the tube as an H2S absorbent. Vacuuming / argon purging was performed ≥3 times, and finally sealed under 0.1MPa argon gas. The sealed reactor was placed in a programmable temperature controlled furnace, heated from 25℃ to 270℃ at a heating rate of 2℃ / min, and held for 3 hours. Cooling stage: Naturally cooled to room temperature to obtain a light yellow powder, namely MOF@Li7P3S 11 Composite solid electrolyte; Li7P3S can be observed by XRD. 11 Characteristic diffraction peaks were observed, and the signal intensity of the impurity phase was low; SEM showed that the MOF morphology was preserved.

[0099] (5) Cold pressing: In the glove box, weigh the composite solid electrolyte obtained in step (4), and apply pressure on the hydraulic press using a hard alloy mold; pressing parameters: pressurization rate 50 MPa / min, target pressure 400 MPa, holding pressure for 3 minutes, depressurization rate 100 MPa / min; a green blank with a relative density of about 85% is obtained.

[0100] (6) Temperature-press densification: The green blank obtained in step (5) is placed in a heated mold and subjected to temperature pressing on a hot press in a glove box. The parameters are: temperature 100℃, pressure 200MPa, holding pressure for 15 minutes to obtain a composite solid electrolyte membrane with a thickness of 100 μm, relative density >95%, and a smooth surface without cracks.

[0101] Compared with Example 1, Examples 2 to 14 and Comparative Examples 2 to 4 each have a single parameter change, as detailed in Table 1. The parameter changes involve: the type and model of the carrier in step (1), whether the impurity removal treatment in step (1) is performed, the molar ratio of Li2S to P2S5 in step (2) (shown as Li2S:P2S5 in Table 1), whether LiI is added in step (2) and the added mass is the percentage of the total mass of the sulfide electrolyte precursor Li2S and P2S5 (shown as LiI / wt%) in Table 1), the mass ratio of the carrier to the precursor mixed powder in step (3) (shown as carrier:sulfide in Table 1), the temperature of the heat treatment in step (4), and the pressing method (where Example 14 omits step (6) warm pressing densification).

[0102] Table 1

[0103]

[0104] The solid electrolyte membranes of Examples 1-14 and Comparative Examples 1-5 were assembled into coin cells: NCM811 positive electrode (capacity 15 mg / cm³) was used. 2The solid electrolyte membrane and the lithium metal anode are stacked in layers from top to bottom; the assembly pressure is 10 MPa, and the assembled battery is dried at 80°C for 12 h to ensure that the internal moisture content is less than 50 ppm.

[0105] Example 15

[0106] The difference from Example 1 is that in step (2), the added mass of LiI is 1 wt% of the total mass of the sulfide electrolyte precursors Li2S and P2S5; and the prepared solid electrolyte membrane is physically spread on one side at a density of 0.1 mg / cm. 2 Amorphous Li3PS4 powder was then lightly pressed at 60°C, 5 MPa, and 5 minutes to form an interface layer; battery assembly: NCM811 cathode (capacity 15 mg / cm³). 2 Li3PS4 interface layer, MOF@Li7P3S 11 The electrolyte and lithium metal anode are stacked in layers from top to bottom; the assembly pressure is 10 MPa, and the assembled battery is dried at 80°C for 12 h to ensure that the internal moisture content is less than 50 ppm.

[0107] Example 16

[0108] The solid electrolyte membrane from Example 1 was assembled with an NCM811 positive electrode and a silicon-carbon composite negative electrode to form a coin cell: NCM811 positive electrode (capacity 15 mg / cm³). 2 MOF@Li7P3S 11 The electrolyte and Si / C negative electrode are stacked in layers from top to bottom; the assembly pressure is 10 MPa, and the assembled battery is dried at 80°C for 12 h to ensure that the internal moisture content is less than 50 ppm.

[0109] Comparative Example 1

[0110] Li₂S and P₂S₅ were mixed at a molar ratio of 2.4:1 and ball-milled (400 rpm, 30 h) under an inert atmosphere to generate Li₇P₃S via a mechanochemical reaction. 11 Solid electrolyte; in a glove box, weigh out Li7P3S 11 Solid electrolyte membranes were prepared by applying pressure on a hydraulic press using a carbide mold; pressing parameters: pressurization rate 50 MPa / min, target pressure 400 MPa, holding pressure for 3 minutes, and depressurization rate 100 MPa / min.

[0111] Performance testing

[0112] Ionic conductivity: Room temperature ionic conductivity verifies the in-situ confined synthesis and integrated composite effect; high temperature ionic conductivity verifies high temperature stability and MOF structure tolerance; low temperature ionic conductivity verifies low temperature performance and ion channel continuity. Electrochemical impedance spectroscopy was used for testing, with a stainless steel | composite electrolyte | stainless steel symmetric cell configuration (both working and counter electrodes are stainless steel sheets). The composite solid electrolyte membrane has a thickness of 100 μm and an effective contact area of ​​2.01 cm². 2 The clamp pressure was kept constant at 5 MPa; the frequency scanning range of the electrochemical workstation was 0.01 Hz to 1 MHz, and the AC amplitude was 10 mV; room temperature ionic conductivity tests were conducted at 25℃, while high-temperature and low-temperature ionic conductivity tests were conducted at 60℃ and 0℃, respectively. After each heating or cooling cycle, the samples were held at the same temperature for 30 min to ensure temperature equilibrium. Ionic conductivity was calculated using the formula σ = L / (R × S), where L is the thickness of the composite solid electrolyte membrane, R is the bulk impedance obtained from the high-frequency intercept of the Nyquist plot, and S is the effective contact area. At least three parallel samples were tested for each sample, and the average value was taken as the final result.

[0113] Relative density was used to verify the densification effect and MOF framework integrity. The test employed a geometric method: after equilibration in a glove box for 24 hours, the diameter or side length and thickness of the electrolyte sheet were measured using precision vernier calipers, and the mass was measured using a precision balance. The theoretical density was calculated using a weighted average of the components, with the formula ρ. 理论 =1 / [(mass fraction of MOF / density of MOF) + (mass fraction of sulfide / density of sulfide)]. Relative density = (measured geometric density / theoretical density) × 100%. At least 3 parallel samples should be measured for each sample.

[0114] The first-cycle coulombic efficiency was measured to verify interface quality and the extent of initial side reactions. The coin cells were subjected to their first charge-discharge cycle at 25°C and a 0.2C rate. The charging mode consisted of constant current charging to the upper limit voltage of 4.3 V, followed by constant voltage charging until the current dropped to the 0.05C cutoff. The discharging mode was constant current discharging to the lower limit voltage of 2.8 V. The first-cycle coulombic efficiency was calculated as (first discharge capacity / first charge capacity) × 100%. The assembly pressure was uniformly set at 10 MPa, and the cells were allowed to stand for 4 hours before formation.

[0115] Cyclic capacity retention was used to verify cycle stability and structural integrity. Tests were conducted at 25°C with a charge / discharge rate of 1C / 1C. The charging regime consisted of a 1C constant current charge to 4.3 V, followed by a constant voltage charge until the current dropped to the 0.05C cutoff. The discharging regime consisted of a 1C constant current discharge to the 2.8 V lower limit voltage. A stacking pressure of 10 MPa was maintained throughout the test to ensure stable contact between the electrodes and the electrolyte. A 0.2C capacity calibration was performed every 50 cycles, recording the discharge capacity at the 1st and 200th cycles. The capacity retention after 200 cycles was calculated as (200th cycle discharge capacity / 1st cycle discharge capacity) × 100%. For long-cycle validation, a 500-cycle test was performed under identical conditions to the 200-cycle test, with a 0.2C capacity calibration performed every 100 cycles.

[0116] Rate performance was assessed to verify kinetic performance and interface impedance. Tests were conducted at 25°C, with sequential charge-discharge cycles at 0.2C, 0.5C, 1C, and 3C rates, each cycle lasting 5 times. The average discharge capacity at each rate was recorded. Rate performance is expressed as the ratio of the 3C discharge capacity to the 0.2C discharge capacity. A stacking pressure of 10 MPa was maintained throughout the test. Three 1C / 1C cycles were performed prior to the rate test to ensure the battery reached a stable state.

[0117] High-temperature storage performance was tested to verify high-temperature stability and long-term interface stability; the test was used to evaluate the long-term stability of the composite electrolyte under high-temperature conditions. At 60°C, the battery was charged at a constant current rate of 1C to 4.3V, then charged at a constant voltage rate until the current dropped to 0.05C, and then discharged at a constant current rate of 1C to 2.8V. This discharge capacity was recorded as the initial capacity C1. The battery was then recharged to 100% SOC and stored at 60°C for 10 days. After storage, the battery was allowed to stand at room temperature for 2 hours, then discharged at a 1C rate to 2.8V, and the capacity was recorded as C2. The capacity retention rate was calculated as (C2 / C1)×100%. Subsequently, three standard cycles were performed at room temperature, and the third discharge capacity C3 was recorded.

[0118] Calculate the capacity recovery rate = (C3 / C1) × 100%.

[0119] Interface stability was tested using a lithium-ion composite electrolyte-lithium symmetric battery configuration (both the working and counter electrodes were lithium sheets), maintaining a stacking pressure of 5 MPa throughout the test. A stepped current ramp method was used, starting from 0.1 mA·cm⁻¹. -2 Initially, the concentration increased by 0.1 mA·cm every 10 hours. -2 Each current density stage employed a cyclic pattern of 0.5 h deposition followed by 0.5 h stripping until the battery short-circuited. The critical current density (CCD) was defined as the last stable current density before failure, and the total stabilization time was the cumulative test duration from the start of the test to failure, to evaluate the ability to suppress lithium dendrite growth and maintain interface stability.

[0120] The test results are shown in Tables 2 and 3.

[0121] Table 2

[0122]

[0123] Table 3

[0124]

[0125] As shown in Table 1:

[0126] Comparative Example 1, prepared using a traditional high-energy ball milling method without introducing a MOF system, showed a decrease in room-temperature ionic conductivity, capacity retention after 200 cycles, and relative density. The core reason is that the traditional ball milling method struggles to avoid sulfide particle agglomeration. During high-energy ball milling, sulfide particles have high surface energy, making them prone to agglomeration into micron-sized or even larger aggregates during preparation and post-processing. This leads to a significant reduction in specific surface area and poor interparticle contact. These agglomerated regions not only fail to provide effective ion conduction but also become stress concentration points, weakening the mechanical properties of the composite material. Furthermore, the traditional method results in a distinct macroscopic phase interface between the sulfide and the polymer matrix. The chemical and physical incompatibility of the two phases forms a high-resistivity layer at the interface, severely limiting ion transport efficiency. The first-cycle coulombic efficiency of Comparative Example 1 also decreased significantly, indicating numerous irreversible side reactions at the interface, causing lithium-ion loss. In terms of cycle performance, the capacity retention rate of Comparative Example 1 dropped to 70% after 200 cycles and further fell below 65% after 500 cycles, indicating that the structural instability and interface degradation caused by aggregation accumulated and intensified with the cycling process. In the rate performance test, its 3C / 0.2C capacity ratio was only 40%, far lower than that of Example 1, indicating that the high-impedance interface severely limited the kinetics of rapid charge and discharge.

[0127] Compared to Example 1, Comparative Example 2 did not undergo a MOF impurity removal step, resulting in residual guest molecules within the MOF channels. This hindered the sufficient entry of precursors into the channels, leading to a lower room-temperature ionic conductivity. This result indicates that MOF impurity removal is a prerequisite for achieving the confined synthesis strategy. Unremoved MOF channels are occupied by residual coordination solvents or guest molecules, forcing precursors to adsorb only on the outer surface of the MOF particles or in larger mesopores. In-situ sulfide formation primarily occurs outside the MOF rather than inside the channels, significantly weakening the nano-confining effect. The relative density, capacity retention after 200 cycles, and first-cycle coulombic efficiency of Comparative Example 2 are all between those of Comparative Example 1 and Example 1, indicating that some confinement effect still exists but is insufficient. In the low-temperature conductivity test, the conductivity of Comparative Example 2 at 0°C is significantly lower than that of Example 1, suggesting insufficient continuity and uniformity of the ion transport channels in Comparative Example 2, resulting in a significant increase in ion transport resistance at low temperatures. By comparing Comparative Example 2 with Example 1, the key role of MOF channel impurity removal in achieving sufficient precursor loading and ensuring uniform in-situ formation of sulfides within the channels was demonstrated.

[0128] Compared to Example 1, Comparative Example 3 employed high-energy ball milling during the precursor loading stage, resulting in damage to the MOF framework structure and partial collapse of the pores. This led to a decrease in its room-temperature ionic conductivity, relative density, and capacity retention after 200 cycles. The damage to the MOF framework caused by high-energy ball milling is multifaceted: the intense mechanical shear force causes the MOF coordination bonds to break, the three-dimensional ordered pore structure to collapse, and a significant decrease in specific surface area and pore volume; the pore collapse renders the originally orderly confined space disordered, and the nucleation and growth of sulfides loses the spatial constraint at the nanoscale, resulting in a wider particle size distribution; the damage to the MOF framework also weakens its mechanical support as a three-dimensional reinforcing phase, reducing the overall mechanical properties of the composite electrolyte. This demonstrates the necessity of a mild loading strategy for protecting the integrity of the MOF framework and ensuring the full utilization of the confinement effect.

[0129] Compared to Example 1, Comparative Example 4, with its heat treatment temperature increased to 300°C, showed a decrease in capacity retention and rate performance after 200 cycles, as well as reduced capacity retention and recovery during high-temperature storage testing. The results indicate that heat treatment at 300°C caused partial damage to the structure, potentially leading to the decomposition or removal of some organic ligands, defects in the pore structure, and a decline in the integrity of the three-dimensional framework. Furthermore, excessively high heat treatment temperatures can promote sulfide grain growth, increasing nanocrystal size, and even causing some sulfides to break through the confinement space of the MOF and migrate outwards. Under harsh conditions such as long-term high-temperature storage, structural defects can accelerate interface degradation and capacity decay. The comparison in Comparative Example 4 verifies the importance of heat treatment temperature in ensuring sufficient reaction of the precursor to generate the target sulfide phase while maintaining the structural integrity of the MOF framework.

[0130] Compared to Example 1, Comparative Example 5, which uses mesoporous silica with nanoscale pores instead of MOF as the support, exhibits lower room-temperature ionic conductivity, first-cycle coulombic efficiency, and capacity retention after 200 cycles compared to Example 1. The fundamental reason for this difference lies in the fact that the organic-inorganic hybrid framework of MOF provides confinement space, while its metal clusters and organic ligands can form chemical bonds or strong interactions with sulfides, achieving atomic / molecular-level interfacial integration. In contrast, inorganic oxides such as silica primarily have physical contact with sulfides, resulting in weak interfacial bonding and high interfacial impedance. Furthermore, the three-dimensional organic ligand network of MOF provides mechanical support, and its pore wall structure may offer additional transport paths for lithium ions, creating a synergistic effect with the bulk conduction of sulfides. Silica itself does not conduct lithium ions, purely serving a physical isolation and support function, which dilutes the overall ionic conductivity. The rate performance of Comparative Example 5 falls between Comparative Example 1 and Example 1, indicating that while the confinement effect exists, interfacial synergy is insufficient. The comparative verification of Example 5 highlights the dual functional role of MOF materials in the technical solution of this application: it serves as both a nanoreactor for confined synthesis and a three-dimensional reinforcing phase for providing mechanical support and ion transport synergy. This integrated structure-function design is the key to achieving good overall performance.

[0131] The systematic comparative verification results of Comparative Examples 1-5 show that the technological contributions of each core technical element in this application exhibit a cumulative and synergistic effect. Compared with the traditional method used in Comparative Example 1, the complete technical solution adopted in the embodiments of this application does not result in a simple linear summation of the effects of each technical means, but rather exhibits a significant multiplier effect. This effect is attributed to the synergistic coupling effect between the technological innovations at the level of this application. The MOF nanoreactor confined synthesis strategy of this application fundamentally changes the preparation paradigm of sulfide composite electrolytes, transforming it from "synthesis first, then composite" to "in-situ integrated generation," from "micron-scale aggregates" to "nanoscale uniform dispersion," and from "high-impedance macroscopic interfaces" to "low-impedance atomic-level interfaces." This transformation brings about a significant improvement in material properties.

[0132] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0133] The embodiments described above are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. It should be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing a solid-state battery cell, characterized in that, Includes the following steps: A modified metal-organic framework material is prepared by removing impurities from a metal-organic framework material; the metal-organic framework material includes a zirconium-based metal-organic framework material; the impurity removal process includes: vacuum removing impurities from the metal-organic framework material at 120℃~200℃ under vacuum conditions; A composite solid electrolyte is prepared by mixing a sulfide electrolyte precursor and the modified metal-organic framework material, followed by ball milling and heat treatment. The sulfide electrolyte precursor includes lithium sulfide and phosphorus pentasulfide. The ball milling speed is 100 rpm to 200 rpm, and the heat treatment temperature is 260℃ to 280℃. The composite solid electrolyte is subjected to a first pressing process to obtain a composite solid electrolyte membrane. The positive electrode, the composite solid electrolyte membrane, and the negative electrode are stacked together, with the composite solid electrolyte membrane disposed between the positive electrode and the negative electrode. After a second pressing process, a solid-state battery cell is obtained.

2. The method for preparing a solid-state battery cell as described in claim 1, characterized in that, The preparation method satisfies at least one of the following characteristics: (1) The heat treatment time is 2 h to 4 h; (2) The heat treatment is carried out under an inert atmosphere; (3) The heating rate to the heat treatment temperature is 1.5℃ / min to 3℃ / min.

3. The method for preparing a solid-state battery cell as described in claim 1, characterized in that, The preparation method satisfies at least one of the following characteristics: (1) The ball milling process is carried out under an inert atmosphere; (2) The ball milling treatment time is 1 h to 2 h.

4. The method for preparing a solid-state battery cell according to any one of claims 1 to 3, characterized in that, The first pressing process is cold pressing, and the temperature of the cold pressing is 4℃~30℃, and the pressure is 300 MPa~500 MPa.

5. The method for preparing a solid-state battery cell as described in claim 4, characterized in that, After the first pressing process, the method further includes: subjecting the blank obtained from the first pressing process to a third pressing process; the third pressing process is selected from warm pressing or cold isostatic pressing.

6. The method for preparing a solid-state battery cell as described in claim 5, characterized in that, The preparation method satisfies one of the following characteristics: (1) The temperature of the temperature-pressure system is 70℃~120℃, and the pressure is 100 MPa~300 MPa; (2) The temperature of the cold isostatic pressing is 4℃~30℃ and the pressure is 200 MPa~400 MPa.

7. The method for preparing a solid-state battery cell according to any one of claims 1-3 and 5-6, characterized in that, The mixture also includes the addition of lithium halide.

8. The method for preparing a solid-state battery cell as described in claim 7, characterized in that, The preparation method satisfies at least one of the following characteristics: (1) The lithium halide includes at least one of lithium iodide and lithium bromide; (2) The mass of the lithium halide is 0.5 wt% to 2 wt% of the total mass of the sulfide electrolyte precursor.

9. The method for preparing a solid-state battery cell according to any one of claims 1-3, 5-6, and 8, characterized in that, The preparation method satisfies at least one of the following characteristics: (1) The mass ratio of the sulfide electrolyte precursor to the modified metal-organic framework material is 1.5~3:1; (2) The pore size of the modified metal-organic framework material is 1.2 nm to 3 nm.

10. The method for preparing a solid-state battery cell according to any one of claims 1-3, 5-6, and 8, characterized in that, The molar ratio of lithium sulfide to phosphorus pentasulfide is 2.2~2.6:

1.

11. The method for preparing a solid-state battery cell according to any one of claims 1-3, 5-6, and 8, characterized in that, The pressure of the second pressing process is 10 MPa to 20 MPa.

12. The method for preparing a solid-state battery cell according to any one of claims 1-3, 5-6, and 8, characterized in that, The layered configuration further includes: an interface layer between the positive electrode and the composite solid electrolyte membrane, the interface layer comprising Li3PS4.

13. A solid-state battery cell, characterized in that, It is prepared by the method of any one of claims 1 to 12 for solid-state battery cells.

14. The solid-state battery cell as described in claim 13, characterized in that, The solid-state battery cell includes a positive electrode, a composite solid-state electrolyte membrane, and a negative electrode stacked together, wherein the composite solid-state electrolyte membrane is disposed between the positive electrode and the negative electrode, and the solid-state battery cell satisfies at least one of the following characteristics: (1) The thickness of the composite solid electrolyte membrane is 60 μm to 300 μm; (2) The porosity of the composite solid electrolyte membrane is ≤5%; (3) The relative density of the composite solid electrolyte membrane is ≥95%; (4) The positive electrode active material of the positive electrode includes at least one of nickel-based ternary materials and lithium iron phosphate materials; (5) The negative electrode active material of the negative electrode includes at least one of lithium, graphite and silicon.

15. A battery device, characterized in that, The battery device includes a solid-state battery cell as described in any one of claims 13 to 14, and the battery device includes at least one of a battery module and a battery pack.

16. An electrical appliance, characterized in that, Includes a solid-state battery cell as described in any one of claims 13 to 14 or a battery device as described in claim 15.

17. An energy storage device, characterized in that, Includes a solid-state battery cell as described in any one of claims 13 to 14 or a battery device as described in claim 15.

Images