Solid electrolyte material, preparation method thereof and battery based on solid electrolyte material

Abstract

The invention discloses a solid-state electrolyte material, a preparation method thereof and a battery based on the solid-state electrolyte material, and belongs to the technical field of solid-state batteries. The solid electrolyte material disclosed by the invention comprises the following components: a main skeleton component used for constructing an amorphous structure frame, an ion source component used for providing a mobile carrier and an auxiliary component used as a functional additive, the molar ratio of the main skeleton component used for constructing the amorphous structure framework to the ion source component used for providing mobile carriers to the auxiliary component used as the functional additive is (1-3): (0.5-1): (0.25-1); according to the invention, a main skeleton component for constructing an amorphous structure frame, an ion source component for providing mobile carriers and an auxiliary component used as a functional additive are used as raw materials, and the three raw materials have a synergistic effect, so that a spatially separated additive strategy can be realized; therefore, the structural integrity is kept, and meanwhile multifunctional cooperative regulation and control are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state batteries, and in particular relates to a solid-state electrolyte material, a preparation method thereof, and a battery based thereon. Background Art

[0002] To enhance the overall performance of high-energy-density energy storage systems, solid-state batteries are becoming a key development direction following liquid lithium-ion batteries due to their superior safety, thermal stability, and structural diversity. As the core material of solid-state batteries, solid electrolytes must not only possess high ionic conductivity and a wide electrochemical stability window, but also be compatible with the positive and negative electrode interfaces, inhibit side reactions, and maintain interfacial stability.

[0003] In traditional liquid electrolyte systems, functional additives are widely used to regulate the interfacial behavior of the electrolyte and are an important means to achieve high-performance battery operation. Additives can be roughly divided into two categories based on their functionality: one is used to stabilize the high-voltage positive electrode interface (such as film formers, oxidation inhibitors), and the other is used to optimize the negative electrode solid electrolyte interface layer (SEI), inhibit dendrite growth or improve interfacial ionic conductivity. However, due to the overall permeability of the liquid system, additives cannot be spatially isolated and must contact the positive and negative electrode interfaces at the same time, which greatly limits their functionality. Some additives may be beneficial to one electrode, but may cause side reactions at the other electrode and become ineffective, which may shorten the battery life. In addition, since it is difficult to simultaneously meet the different electrochemical requirements of the positive and negative electrodes, the screening space for additives is significantly compressed.

[0004] In contrast, solid electrolyte materials, due to their solid-state distribution characteristics, provide new possibilities for the targeted design and regional deployment of functional additives. The layered design strategy proposed in recent years, that is, the use of halide electrolytes with high voltage stability on the positive electrode side and sulfide electrolytes that are more compatible with negative electrodes such as lithium metal on the negative electrode side, is expected to improve overall performance. However, this strategy still faces significant challenges in practical applications: there is usually strong chemical incompatibility between halides and sulfides, and violent reactions are prone to occur at the contact interface, forming a high-impedance interface layer, which in turn inhibits ion transport and reduces the overall performance of the battery.

[0005] Therefore, there is an urgent need to develop a solid electrolyte material system that is structurally unified but functionally adjustable. This would not only overcome the interface reaction limitations of existing layered material systems, but also preserve the freedom to use functional additives for both the positive and negative electrodes, achieving a better match between the electrolyte and the electrode. Summary of the Invention

[0006] The purpose of the present invention is to provide a solid electrolyte material and a preparation method thereof and a battery based thereon, so as to solve the technical problem that existing solid electrolytes are difficult to have structural uniformity and regional adjustability.

[0007] To achieve the above object, the present application adopts the following technical solutions: The present application discloses a kind of solid electrolyte materials, the composition of the solid electrolyte material includes: The main skeleton component for constructing amorphous structure framework, the ion source component for providing mobile carrier and the auxiliary component used as functional additive; The molar ratio of the main skeleton component for constructing amorphous structure framework, the ion source component for providing mobile carrier and the auxiliary component used as functional additive is (0.05~3): (0.05~1): (0~1).

[0008] Further, the main skeleton component for constructing amorphous structure framework is metal halide MX y ; Wherein, M represents at least one of Zr, Hf, Ta, Nb, Al, Fe and Ga;X represents at least one of F, Cl, Br and I;Y is stoichiometric coefficient, y is 3, 4 or 5.

[0009] Further, the ion source component for providing mobile carrier is oxygen-containing lithium salt Li (A) O m ; Wherein, A represents at least one of B, S, P, Si, As, Mo, W and C;M is stoichiometric coefficient, and m is 2, 3 or 4.

[0010] Further, the auxiliary component used as functional additive is positive electrode stabilizer, negative electrode interface control agent, high ionic conductivity enhancer or flame retardant.

[0011] Further, the auxiliary component used as functional additive is one or more of LiF, LiNO3, Li3N, LiFSI, LiTFSI, TiF4, AlF3 and Li2S.

[0012] The present application also discloses the preparation method of the above-mentioned solid electrolyte material, comprising the following steps: According to the requirements of positive electrode side, negative electrode side or middle layer area, the main skeleton component for constructing amorphous structure framework, the ion source component for providing mobile carrier and the auxiliary component used as functional additive are selected, and the above-mentioned materials to be used are weighed according to the molar ratio described above;Then, the above-mentioned materials to be used are mixed uniformly under inert atmosphere, to obtain solid electrolyte material.

[0013] Further, the mixing is first hand grinding and then mixing treatment;The mixing treatment adopts mechanical ball milling method, solvent assisted ball milling method or melt quenching method; The process parameters of the mechanical ball milling method are: The ball milling beads are 3-10 mm in diameter, the ball-to-material ratio is (60:1)-(20:1), the ball milling time is 1-30 h, and the ball milling speed is 400-800 r / min.

[0014] Further, the types of the solid-state electrolyte material include a positive electrode-side solid-state electrolyte material, a negative electrode-side solid-state electrolyte material, and an intermediate layer region solid-state electrolyte material; When the positive electrode-side solid-state electrolyte material, the auxiliary component used as a functionalized additive is LiF, LiTFSI, TiF4, and AlF3; When the negative electrode-side solid-state electrolyte material, the auxiliary component used as a functionalized additive is LiF, LiNO3, Li3N, LiFSI, LiTFSI, and Li2S; When the intermediate layer region solid-state electrolyte material, the auxiliary component used as a functionalized additive is Li2O, Li3PO4, Li4SiO4, Li2CO3; or no auxiliary component used as a functionalized additive is added; The inert atmosphere is in a water-free and oxygen-free environment.

[0015] The application further discloses a battery comprising the above-mentioned solid-state electrolyte material, the battery comprising a positive electrode sheet, a negative electrode sheet, and a solid-state electrolyte layer between the positive electrode sheet and the negative electrode sheet. The solid-state electrolyte layer is obtained by pressing the solid-state electrolyte material according to the application.

[0016] Further, the positive electrode sheet is obtained by cold pressing or coating a positive electrode active material and a positive electrode filler; The positive electrode active material comprises at least one of cobalt-aluminum oxide, lithium iron phosphate, lithium-rich phase lithium manganese oxide, lithiated layered oxide, and lithiated layered sulfide; The positive electrode filler is at least one of an ion-conducting agent, an electrically conductive agent, and a binder; the ion-conducting agent is the same as the solid-state electrolyte material between the positive electrode sheet and the negative electrode sheet; the electrically conductive agent is at least one of graphite, carbon black, acetylene black, ketjen black, and carbon fiber; and the binder is at least one of styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene; The negative electrode sheet is obtained by cold pressing or coating a negative electrode active material and a negative electrode filler; the negative electrode active material is a material capable of storing and releasing A ions; the negative electrode filler is at least one of an ion-conducting agent, an electrically conductive agent, and a binder; the ion-conducting agent is the same as the solid-state electrolyte material between the positive electrode sheet and the negative electrode sheet; the electrically conductive agent is at least one of graphite, carbon black, acetylene black, ketjen black, and carbon fiber; and the binder is at least one of styrene butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene; The pressing mode is cold pressing.

[0017] Compared with the prior art, the present application has the following beneficial effects: The application discloses a kind of solid electrolyte materials, by setting up for constructing amorphous structure framework main skeleton component, for providing mobile carrier ion source component and as functional additive auxiliary component as raw material, three raw materials synergistic effect, wherein for constructing amorphous structure framework main skeleton component provides inorganic skeleton, for providing mobile carrier ion source component introduces mobile ion carrier, as functional additive auxiliary component can be according to the position where final solid electrolyte material is located and endows specific functionalization behavior, i.e. it can realize spatial separation type additive strategy, so as to realize multifunctional synergistic regulation while maintaining the integrity of structure;The solid electrolyte material disclosed in the application can introduce functional components in the same parent electrolyte framework, realize the performance differentiation regulation of electrolyte body, avoid the chemical incompatibility problem between different crystal phases.

[0018] Further, the application also discloses a solid electrolyte material with long-range disordered amorphous state characteristics, the main skeleton component for constructing amorphous structure framework and the ion source component for providing mobile carrier form the unified basic framework of electrolyte material, and the auxiliary component as functional additive can be regionally doped according to the spatial position, for respectively regulating the functional requirements of positive electrode side, negative electrode side and intermediate layer region.

[0019] Further, the main skeleton component for constructing amorphous structure framework is metal halide MX y The material forms short-range disordered amorphous structure, part of halogen in M-X polyhedron can be replaced by oxygen, to constitute a random network composed of main skeleton component for constructing amorphous structure framework, ion source component for providing mobile carrier;Regionally introduced auxiliary component as functional additive is controlled in electrolyte distribution, to realize structure-function coupling regulation, according to use requirement, auxiliary component as functional additive can also not be added;The structure has good ion migration channel, and the overall material shows excellent room temperature ionic conductivity.

[0020] The application also discloses a preparation method of the solid-state electrolyte material, wherein in the preparation process, the required material is selected according to the requirements of the positive electrode side, the negative electrode side or the middle layer region, the positive electrode side can introduce an oxidation stabilizer or an electron blocking component, including one or more of LiF, LiTFSI, TiF4 and AlF3; the negative electrode side can use an SEI generation promoter or an interface passivator, including one or more of LiF, LiNO3, Li3N, LiFSI, LiTFSI and Li2S; and the middle region can strengthen the ion conduction performance, so that the multifunctional synergistic regulation is realized while the structural integrity is maintained; the preparation method has a simple process route and controllable steps, is suitable for the doping strategy under the functional requirements of different regions, avoids the interface reaction problem of the multiphase electrolyte, and improves the overall battery stability and processability.

[0021] The application also discloses a battery comprising the solid-state electrolyte material, wherein the solid-state electrolyte layer of the battery is a multi-region integrated electrolyte sheet pressed from the solid-state electrolyte material, and the battery has good structural continuity and interface adaptability. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 X-ray diffraction spectra of the solid-state electrolyte materials prepared in Embodiment 1 to Embodiment 3 of the application; Figure 2 Changes in electrochemical impedance spectra of the solid-state electrolyte material stacks prepared in Embodiment 3 and Embodiment 4 of the application; Figure 3 Changes in electrochemical impedance spectra of common halide electrolyte Li2ZrCl6 and Li6PS5Cl electrolyte stacks; Figure 4 Charge-discharge curves of the solid-state battery provided in Embodiment 7. DETAILED DESCRIPTION

[0023] In order for those skilled in the art to understand the characteristics and effects of the application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used in the text are the usual meanings understood by those skilled in the art for the application, and in case of conflict, the definition in the specification shall prevail.

[0024] Theories or mechanisms described and disclosed herein, whether correct or not, should not be used to limit the scope of the application, that is, the content of the application can be implemented without being limited by any particular theory or mechanism.

[0025] Herein, all features defined by a numerical range or a percentage range, such as numerical values, amounts, contents and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of the numerical range or the percentage range should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0026] Herein, unless otherwise specifically stated, "comprise", "include", "contain", "have" or similar terms, encompass both "consist of" and "consist essentially of", for example, "A comprises a" encompasses both "A comprises a and others" and "A consists of a only".

[0027] Herein, for the sake of brevity of the description, all possible combinations of the various technical features in the various embodiments or examples are not described. Therefore, the various technical features in the various embodiments or examples can be combined with each other in any manner as long as there is no contradiction, and all possible combinations should be considered to be within the scope of the present specification.

[0028] The first aspect of the present application provides a solid-state electrolyte material, the composition of which comprises: a main skeleton component for constructing an amorphous structure framework, an ion source component for providing mobile carriers, and an auxiliary component for serving as a functionalization additive; the molar ratio of the main skeleton component for constructing an amorphous structure framework, the ion source component for providing mobile carriers, and the auxiliary component for serving as a functionalization additive is (0.05-3): (0.05-1): (0-1); The main skeleton component for constructing an amorphous structure framework is a metal halide MX y ; M represents at least one of Zr, Hf, Ta, Nb, Al, Fe and Ga; X represents at least one of F, Cl, Br and I; y is a stoichiometric coefficient, y is 3, 4 or 5; The ion source component for providing mobile carriers is an oxygen-containing lithium salt Li(A)O m ; A represents at least one of B, S, P, Si, As, Mo, W and C; m is a stoichiometric coefficient, m is 2, 3 or 4; The auxiliary component for serving as a functionalization additive has different functionalities in different electrode regions, including but not limited to positive electrode stabilizers, negative electrode interface control agents, high ionic conductivity enhancers, flame retardants, etc., and the additive is selected from one or more of LiF, LiNO3, Li3N, LiFSI, LiTFSI, TiF4, AlF3, Li2S.

[0029] Preferably, the solid-state electrolyte material has long-range disordered amorphous characteristics; the main skeleton component for constructing the amorphous structure framework and the ion source component for providing mobile carriers form a unified basic framework of the electrolyte material, and the auxiliary component serving as a functional additive can be regionally doped according to the spatial position, for regulating the functional requirements of the positive electrode side, the negative electrode side and the intermediate layer region, respectively.

[0030] Preferably, the material forms a short-range disordered amorphous structure, part of the halogen in the M-X polyhedron can be replaced by oxygen, constituting a random network composed of the main skeleton component for constructing the amorphous structure framework, the ion source component for providing mobile carriers; the auxiliary component serving as a functional additive regionally introduced is controlled in distribution in the electrolyte, realizing structure-function coupling regulation; the structure has good ion migration channels, and the overall material exhibits excellent room-temperature ionic conductivity.

[0031] Preferably, the solid-state electrolyte material further comprises an amorphous phase and a small amount of nanocrystalline phase. The crystalline phase is a Li x M y X z or LiX phase, with a particle size of nanoscale, embedded in the amorphous matrix. Lithium ions mainly migrate in the amorphous matrix and the crystal / amorphous interface.

[0032] The second aspect of the present application provides a preparation method of the above-mentioned solid-state electrolyte material, comprising the following steps: Under anhydrous and anaerobic inert atmosphere (preferably Ar), the main skeleton component for constructing the amorphous structure framework and the ion source component for providing mobile carriers are mixed according to the above-mentioned molar ratio, and the required functional additives (auxiliary components serving as functional additives) are introduced in different regions, respectively, to synthesize the amorphous electrolyte material (solid-state electrolyte material) by any of the following technical routes, such as mechanical ball milling method; solvent-assisted ball milling method; melt quenching method; or other means that can realize amorphous structure.

[0033] Preferably, during the mechanical ball milling process, the control parameters meet at least one of the following (1)~(4): (1) the ball milling beads are 3~10 mm in diameter; (2) the ratio of material to ball is (60:1)~(20:1); (3) the ball milling time is 1~30 h; (4) the rotation speed of the ball mill is 400~800 r / min.

[0034] More preferably, the ball milling beads are 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm in diameter, etc.

[0035] More preferably, the ball-to-material ratio is 60:1, 50:1, 40:1, 30:1, or 20:1, etc.

[0036] More preferably, the ball milling time is 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 20 h, or 30 h, etc.

[0037] More preferably, the ball mill rotation speed is 400 r / min, 500 r / min, 600 r / min, 700 r / min, or 800 r / min, etc.

[0038] More preferably, the control parameters satisfy: the ball milling beads are 3-5 mm in diameter, the ball-to-material ratio is (60:1)-(30:1), the ball milling time is 1-8 h, and the ball mill rotation speed is 400-550 r / min.

[0039] Preferably, the method further comprises a premixing step: the components required by each region, i.e., the main skeleton component for building the amorphous structure framework, the ion source component for providing mobile carriers, and the corresponding functional additives (used as auxiliary components of the functional additives), are premixed to form “positive electrode side mixed powder”, “negative electrode side mixed powder”, and “interlayer mixed powder”, which are then ball milled to obtain functional electrolyte master powder; this method helps to improve the uniformity and controllability of the regional additive distribution.

[0040] Preferably, the inert atmosphere free of water and oxygen is N2 or Ar gas; more preferably, Ar gas is used; the premixing can be performed by mortar hand grinding or mixer mixing, etc.

[0041] The third aspect of the present application discloses a battery comprising the above-mentioned solid electrolyte material; the battery comprises a positive electrode sheet, a negative electrode sheet, and a solid electrolyte layer therebetween, wherein the solid electrolyte layer is a multi-region integrated electrolyte sheet obtained by pressing the above-mentioned solid electrolyte material; the electrolyte sheet is composed of a basic framework (the main skeleton component for building the amorphous structure framework and the ion source component for providing mobile carriers) and spatially selectively distributed functional additives (used as auxiliary components of the functional additives), and has good structural continuity and interface adaptability.

[0042] The solid electrolyte layer comprises at least two layers of positive electrode side electrolyte and negative electrode side electrolyte, both of which contain the same main skeleton component for building the amorphous structure framework and the ion source component for providing mobile carriers, and different auxiliary components of the functional additives; preferably, one or more layers of interlayer electrolyte are further included, which functions to prevent short circuit, flame retardant, improve ionic conductivity, etc.

[0043] Preferably, the solid electrolyte sheet is obtained by cold pressing the solid electrolyte material.

[0044] Preferably, the positive electrode sheet is obtained by cold-pressing or coating the positive electrode active material and the positive electrode filler. The positive electrode active material includes, but is not limited to, at least one of cobalt-aluminum oxide, lithium iron phosphate, lithium-rich phase lithium manganese oxide, lithiated layered oxide, and lithiated layered sulfide. The positive electrode filler is at least one of an ion-conducting agent, an electrically conductive agent, and a binder; the ion-conducting agent is the same material as the solid-state electrolyte between the positive and negative electrodes of the battery; the electrically conductive agent can include at least one of graphite, carbon black, acetylene black, ketjen black, and carbon fiber; and the binder can include at least one of, for example, styrene-butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene. The cold-pressing or coating method is a common method for preparing a positive electrode sheet in the art.

[0045] Preferably, the negative electrode sheet is obtained by cold-pressing or coating the negative electrode active material and the negative electrode filler. The negative electrode active material refers to a material capable of storing and releasing A ions, including but not limited to a metal material, graphite, or silicon; the metal material can be a simple metal or an alloy; when a metal material is used as the negative electrode active material, the negative electrode filler can not be used. The negative electrode filler is at least one of an ion-conducting agent, an electrically conductive agent, and a binder; the ion-conducting agent is the same material as the solid-state electrolyte between the positive and negative electrodes of the battery; the electrically conductive agent can include at least one of graphite, carbon black, acetylene black, ketjen black, and carbon fiber; and the binder can include at least one of, for example, styrene-butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene. The cold-pressing or coating method is a common method for preparing a negative electrode sheet in the art.

[0046] The present application is further described in conjunction with the following specific examples. It should be understood that these examples are merely for the purpose of illustration and are not intended to limit the scope of the present application. Furthermore, it should be understood that various modifications and alterations might be made by those skilled in the art upon reading the teachings of the present application, and that such modifications and alterations are also within the scope of the appended claims.

[0047] The following examples use conventional equipment in the art. The experimental methods in the following examples, unless otherwise specified, are generally performed according to conventional conditions, or according to the conditions recommended by the manufacturer. The following examples use various raw materials, unless otherwise specified, all of which are conventional commercially available products, and the specifications thereof are conventional specifications in the art. In the specification of the present application and in the following examples, unless otherwise specified, "%" means weight percent, "parts" means weight parts, and the ratio means weight ratio.

[0048] Example 1 A method for preparing a solid-state electrolyte material includes the following steps: In this embodiment, the main skeleton component for constructing an amorphous structure framework, the ion source component for providing mobile carriers, and the auxiliary component for functionalization as additives are TaCl5, Li3PO4, and AlF3, respectively. The TaCl5, Li3PO4 and AlF3 are weighed according to the molar ratio of 3:1:0.5, mixed, and ground by hand for 10 min using an agate mortar to fully mix, to obtain the mixed powder; 1 g of the mixed powder is transferred to a 75 mL ball mill jar, and 40 g of grinding beads with a diameter of 3 mm are added accordingly. The ball mill jar is then vacuumed, sealed, and ball milled on a planetary ball mill at a speed of 600 r / min for 5 h. After the ball milling is completed, the ball mill jar is transferred to a glove box, opened, and the powder in the jar is taken out, which is the synthesized 3TaCl5-Li3PO4-0.5AlF3 positive electrode side solid-state electrolyte (solid-state electrolyte material).

[0049] Example 2 A method for preparing a solid-state electrolyte material, comprising the following steps: In this embodiment, the main skeleton component for constructing an amorphous structure framework, the ion source component for providing mobile carriers, and the auxiliary component used as a functional additive are TaCl5, Li3PO4 and LiNO3, respectively; The TaCl5, Li3PO4 and LiNO3 are weighed according to the molar ratio of 2:1:1, mixed, and ground by hand for 10 min using an agate mortar to fully mix, to obtain the mixed powder; 1 g of the mixed powder is transferred to a 75 mL ball mill jar, and 40 g of grinding beads with a diameter of 3 mm are added accordingly. The ball mill jar is then vacuumed, sealed, and ball milled on a planetary ball mill at a speed of 600 r / min for 5 h. After the ball milling is completed, the ball mill jar is transferred to a glove box, opened, and the powder in the jar is taken out, which is the synthesized 2TaCl5-Li3PO4-LiNO3 negative electrode side solid-state electrolyte (solid-state electrolyte material).

[0050] Example 3 A method for preparing a solid-state electrolyte material, comprising the following steps: In this embodiment, the main skeleton component for constructing an amorphous structure framework, the ion source component for providing mobile carriers, and the auxiliary component used as a functional additive are HfCl4, Li2CO3 and LiBF4, respectively; The HfCl4, Li2CO3 and LiBF4 are weighed according to the molar ratio of 1:1:0.5, mixed, and ground by hand for 10 min using an agate mortar to fully mix, to obtain the mixed powder; 1 g of the mixed powder was transferred into a 75 mL ball mill jar, and 40 g of grinding beads with a diameter of 3 mm were added accordingly. Then the ball mill jar was evacuated and sealed, and ball milling was performed on a planetary ball mill at a rotation speed of 600 r / min for 5 h. After the ball milling was completed, the ball mill jar was transferred into a glove box, opened, and the powder in the jar was taken out, which was the synthesized HfCl4-Li2CO3-0.5LiBF4 positive electrode side solid-state electrolyte (solid-state electrolyte material).

[0051] Example 4 A method for preparing a solid-state electrolyte material, comprising the following steps: In this embodiment, the main skeleton component for constructing an amorphous structure framework, the ion source component for providing mobile carriers, and the auxiliary component serving as a functionalized additive were HfCl4, Li2CO3, and Li2S, respectively; HfCl4, Li2CO3, and Li2S were weighed according to a molar ratio of 1:1:1, and the weighed HfCl4, Li2CO3, and Li2S were mixed and hand-ground in a agate mortar for 10 min for sufficient mixing to obtain a mixed powder; 1 g of the mixed powder was transferred into a 75 mL ball mill jar, and 40 g of grinding beads with a diameter of 3 mm were added accordingly. Then the ball mill jar was evacuated and sealed, and ball milling was performed on a planetary ball mill at a rotation speed of 600 r / min for 5 h. After the ball milling was completed, the ball mill jar was transferred into a glove box, opened, and the powder in the jar was taken out, which was the synthesized HfCl4-Li2CO3-Li2S positive electrode side solid-state electrolyte (solid-state electrolyte material).

[0052] Example 5 A method for preparing a solid-state electrolyte material, comprising the following steps: In this embodiment, the main skeleton component for constructing an amorphous structure framework, the ion source component for providing mobile carriers, and the auxiliary component serving as a functionalized additive were HfCl4, Li2CO3, and Li4SiO4, respectively; HfCl4, Li2CO3, and Li4SiO4 were weighed according to a molar ratio of 1:1:1, and the weighed HfCl4, Li2CO3, and Li4SiO4 were mixed and hand-ground in a agate mortar for 10 min for sufficient mixing to obtain a mixed powder; 1 g of the mixed powder was transferred into a 75 mL ball mill jar, and 40 g of grinding beads with a diameter of 3 mm were added accordingly. Then the ball mill jar was evacuated and sealed, and ball milling was performed on a planetary ball mill at a rotation speed of 600 r / min for 5 h. After the ball milling was completed, the ball mill jar was transferred into a glove box, opened, and the powder in the jar was taken out, which was the synthesized HfCl4-0.5Li2CO3-0.25Li4SiO4 positive electrode side solid-state electrolyte (solid-state electrolyte material).

[0053] Example 6 A method for preparing a solid-state electrolyte material, comprising the following steps: In this embodiment, the main skeleton component for constructing an amorphous structure framework and the ion source component for providing mobile carriers are TaCl5 and Li4SiO4, respectively, without adding an auxiliary component as a functional additive.

[0054] According to the molar ratio of TaCl5 and Li4SiO4 as 1:0.5, the weighed TaCl5 and Li4SiO4 are mixed, and a hand mortar is used for 10 min to fully mix, to obtain a mixed powder; 1 g of the mixed powder is transferred to a 75 mL ball mill tank, and 40 g of grinding beads with a diameter of 3 mm are added accordingly. After that, the ball mill tank is vacuumized and sealed. The ball milling is carried out on a planetary ball mill at a rotation speed of 600 r / min for 5 h. After the ball milling is completed, the ball mill tank is transferred to the glove box to be opened, and the powder in the tank is taken out, which is the synthesized TaCl5-0.5Li4SiO4 intermediate solid-state electrolyte (solid-state electrolyte material).

[0055] Example 7 The present embodiment provides a solid-state electrolyte material comprising the solid-state electrolyte material prepared in Example 1 and Example 2; The specific assembly process is as follows: Step 1: Weigh commercially available lithium layered oxide LiNi 0.88 Co 0.09 Mn 0.03 O2 (as a positive active material), 3TaCl5-Li3PO4-0.5AlF3 (as an ion conducting agent) and carbon black (as an electron conducting agent) in a mass ratio of 7:3:0.1, and manually grind in a mortar for 10 min to uniformly mix, to form a composite positive electrode; Step 2: Weigh 50 mg of the positive electrode side solid-state electrolyte 3TaCl5-Li3PO4-0.5AlF3 powder synthesized in Example 1, and cold-press into a solid-state electrolyte sheet with a diameter of 10 mm at a pressure of 100 MPa for 2 min. Weigh 50 mg of 2TaCl5-Li3PO4-LiNO3 synthesized in Example 2 as a negative electrode side electrolyte, and uniformly spread on one side surface of the 3TaCl5-Li3PO4-0.5AlF3 solid-state electrolyte sheet, and cold-press at a pressure of 100 MPa for 2 min; Step 3: Weigh 10 mg of the composite positive electrode prepared in Step 1, and uniformly spread on the other side surface of the 3TaCl5-Li3PO4-0.5AlF3 solid-state electrolyte sheet prepared in Step 2, and cold-press at a pressure of 350 MPa for 2 min; Step 4: Using commercially available indium sheet (diameter of 10 mm, thickness of 200 μm) as negative active material, pasted on the other side surface of the 2TaC15-Li3P04-LiN03 barrier layer prepared in Step 2, forming a "positive electrode sheet-positive side solid-state electrolyte-negative side solid-state electrolyte-negative electrode sheet" three-layer structure, and applying a pressure of 100 MPa to the whole to complete the assembly to obtain a full solid-state lithium battery; The steps 1-4 are all carried out in an argon atmosphere glove box without water and oxygen.

[0056] Example 8 The present example provides a solid-state electrolyte material comprising the solid-state electrolyte material prepared in Example 3 and Example 4; The specific assembly process is as follows: Step 1: Take commercially available lithium layered oxide LiNi 0.88 Co 0.09 Mn 0.03 O2(as positive active material), HfCl4-Li2CO3-0.5LiBF4(as ion conductor) and carbon black (as electronic conductor), mass ratio of 7:3:0.1, manually ground in a mortar for 10 min to uniformly mix, forming a composite positive electrode; Step 2: Take 50 mg of the positive side solid-state electrolyte HfCl4-Li2CO3-0.5LiBF4 powder synthesized in Example 3, cold-pressed into a solid-state electrolyte sheet with a diameter of 10 mm, pressure of 100 MPa, and pressure holding time of 2 min; take 50 mg of HfCl4-Li2CO3-Li2S synthesized in Example 4 as negative side electrolyte, uniformly spread on one side surface of the HfCl4-Li2CO3-0.5LiBF4 solid-state electrolyte sheet, cold-pressed, pressure of 100 MPa, and pressure holding time of 2 min.

[0057] Step 3: Take 10 mg of the composite positive electrode prepared in Step 1, uniformly spread on the other side surface of the HfCl4-Li2CO3-0.5LiBF4 solid-state electrolyte sheet prepared in Step 2, cold-pressed, pressure of 350 MPa, and pressure holding time of 2 min; Step 4: Using commercially available indium sheet (diameter of 10 mm, thickness of 200 μm) as negative active material, pasted on the other side surface of the HfCl4-Li2CO3-Li2S barrier layer prepared in Step 2, forming a "positive electrode sheet-positive side solid-state electrolyte-negative side solid-state electrolyte-negative electrode sheet" three-layer structure, and applying a pressure of 100 MPa to the whole to complete the assembly to obtain a full solid-state lithium battery; The steps 1-4 are all carried out in an argon atmosphere glove box without water and oxygen.

[0058] Example 9 The present embodiment provides a solid-state electrolyte material comprising the solid-state electrolyte material prepared in Embodiment 3 and Embodiment 4; The specific assembly process is as follows: Step 1: Take commercially available lithium layered oxide LiNi 0.88 Co 0.09 Mn 0.03 O2(as a positive active material), HfCl4-Li2CO3-0.5LiBF4(as an ion-conducting agent) and carbon black (as an electron-conducting agent) in a mass ratio of 7:3:0.1, and manually grind in a mortar for 10 min to form a uniform mixture, forming a composite positive electrode.

[0059] Step 2: Take 40 mg of the positive-side solid-state electrolyte HfCl4-Li2CO3-0.5LiBF4 powder synthesized in Embodiment 3, and cold-press into a solid-state electrolyte sheet with a diameter of 10 mm at a pressure of 100 MPa for 2 min. Take 40 mg of the HfCl4-0.5Li2CO3-0.25Li4SiO4 solid-state electrolyte synthesized in Embodiment 5 as an intermediate-side electrolyte, and evenly spread on one side surface of the HfCl4-Li2CO3-0.5LiBF4 solid-state electrolyte sheet at a pressure of 100 MPa for 2 min; take 40 mg of the HfCl4-Li2CO3-Li2S synthesized in Embodiment 4, and cold-press at a pressure of 100 MPa for 2 min; Step 3: Take 10 mg of the composite positive electrode prepared in Step 1, and evenly spread on the other side surface of the HfCl4-Li2CO3-0.5LiBF4 solid-state electrolyte sheet prepared in Step 2, and cold-press at a pressure of 350 MPa for 2 min; Step 4: Use a commercially available indium sheet (diameter of 10 mm, thickness of 200 μm) as a negative active material, and attach it to the other side surface of the HfCl4-Li2CO3-Li2S barrier layer prepared in Step 2, to form a three-layer structure of “positive electrode sheet-positive-side solid-state electrolyte-negative-side solid-state electrolyte-negative electrode sheet”, and apply a pressure of 100 MPa to the whole to complete the assembly to obtain a full-solid-state lithium battery; The steps 1 to 4 are all carried out in an argon glove box in anhydrous and oxygen-free atmosphere.

[0060] Performance characterization analysis: 1. Ion conductivity characterization analysis (1) Characterization method In an anhydrous and oxygen-free argon atmosphere glove box, the solid electrolyte materials prepared in Examples 1 to 5 were filled into a cylindrical tablet mold (diameter 10 mm); and cold pressed at a pressure of 375 MPa for 2 min to obtain a solid electrolyte sheet with a thickness of 0.5-1.5 mm and a diameter of 10 mm. After gold plating on the upper and lower surfaces of the solid electrolyte sheet, two stainless steel blocking electrodes were used to clamp the upper and lower surfaces, and the sheet was connected to an electrochemical workstation to measure the electrochemical impedance spectroscopy at room temperature. The room temperature Li + Ionic conductivity.

[0061] (2) Characterization results Table 1 shows the ionic conductivities of the solid electrolytes synthesized in Examples 1 to 5.

[0062] Table 1 Ionic conductivity of solid electrolytes

[0063] 2. Crystal Structure Characterization and Analysis (1) Characterization method The solid electrolytes prepared in Example 3, Example 4, and Example 5 were characterized using an X-ray diffractometer.

[0064] (2) Characterization results Figure 1 The XRD spectra of the solid electrolyte materials prepared in Examples 3, 4, and 5 were characterized. In the figure, the abscissa represents the diffraction angle (2 Theta), in degrees (°); the ordinate represents the diffraction intensity. The results show that these solid electrolyte materials all exhibit broadened diffraction peaks, indicating that the solid electrolyte is mostly a disordered amorphous phase.

[0065] 3. Chemical reactivity of the solid electrolyte layer (1) Characterization method The solid electrolytes prepared by stacking 80 mg of HfCl4-Li2CO3-0.5LiBF4 in Example 3 and 80 mg of HfCl4-Li2CO3-Li2S in Example 4 were pressed into sheets to measure the change of electrochemical impedance spectroscopy over time.

[0066] (2) Characterization results Figure 2 The changes in the electrochemical impedance spectra of the solid electrolyte stack prepared by HfCl4-Li2CO3-0.5LiBF4 in Example 3 and HfCl4-Li2CO3-Li2S in Example 4 are characterized. In the figure, the horizontal axis represents the real resistance in ohms (Ω); the vertical axis represents the imaginary resistance in ohms (Ω); for comparison, Figure 3The change of electrochemical impedance spectrum of the common halide electrolyte Li2ZrCl6 and Li6PS5Cl electrolyte stack is characterized, in which the abscissa represents the real part resistance, unit is ohm (Ω); the ordinate represents the imaginary part resistance, unit is ohm (Ω); the results show that the resistance of the solid-state electrolyte stack prepared by HfCl4-Li2CO3-0.5LiBF4 in Example 3 and HfCl4-Li2CO3-Li2S in Example 4 increases by about 3% after 12h, and the impedance of Li2ZrCl6 and Li6PS5Cl electrolyte stack in the control group increases by about 9% after 12h. This shows that the introduction of functional components in the same parent electrolyte framework can realize the chemical compatibility of the multi-layer electrolyte.

[0067] 4. Electrochemical performance test (1) Test method At room temperature, the solid-state battery provided in Example 8 was subjected to constant current charge and discharge test using a blue electric battery test system, and the voltage range was 2.5 V~4.5 V (voltage relative to Li + / Li), and the first 3 weeks of cycling were carried out at 0.1 C rate. The charge and discharge curves of the solid-state battery provided in Example 8 in the first week and the second week of cycling are shown in Figure 4 .

[0068] (2) Test results The test results are shown in Figure 4 , in which the abscissa represents the specific capacity, unit is milliampere-hour per gram (mAh g -1 ); the ordinate represents the voltage (voltage relative to Li + / Li), unit is volt (V).

[0069] The solid-state battery provided in Example 8 has a reversible capacity of 137.5 mAh g -1 at 0.1 C rate in the first week.

[0070] The above content only illustrates the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical solution falls within the protection scope of the claims of the present application.

Claims

1. A solid electrolyte material, characterized in that The components of the solid electrolyte material include: A main skeleton component for constructing an amorphous structural framework, an ion source component for providing mobile carriers, and an auxiliary component used as a functional additive; The molar ratio of the main skeleton component for constructing the amorphous structure framework, the ion source component for providing mobile carriers and the auxiliary component used as a functional additive is (0.05-3): (0.05-1): (0-1).

2. A solid electrolyte material according to claim 1, characterized in that: The main skeleton component for constructing the amorphous structural framework is a metal halide MX y ; Wherein, M represents at least one of Zr, Hf, Ta, Nb, Al, Fe and Ga; X represents at least one of F, Cl, Br and I; y is a stoichiometric coefficient, and y is 3, 4 or 5.

3. A solid electrolyte material according to claim 1, characterized in that: The ion source component for providing mobile carriers is an oxygen-containing lithium salt Li(A)O m ; Wherein, A represents at least one of B, S, P, Si, As, Mo, W and C; m is the stoichiometric coefficient, which is 2, 3 or 4.

4. A solid electrolyte material according to claim 1, characterized in that: The auxiliary component used as the functional additive is a positive electrode stabilizer, a negative electrode interface regulator, a high ion conductivity enhancer or a flame retardant.

5. A solid electrolyte material according to claim 1, characterized in that: The auxiliary component used as the functional additive is one or more of LiF, LiNO3, Li3N, LiFSI, LiTFSI, TiF4, AlF3 and Li2S.

6. The method for preparing a solid electrolyte material according to any one of claims 1 to 5, characterized in that: The following steps are involved: According to the requirements of the positive electrode side, the negative electrode side or the intermediate layer area, the main skeleton component for constructing the amorphous structure framework, the ion source component for providing mobile carriers and the auxiliary component used as a functional additive are selected, and they are weighed and set aside according to the molar ratio described in claim 1; then the above-mentioned materials are mixed evenly under an inert atmosphere to obtain a solid electrolyte material.

7. The method for preparing a solid electrolyte material according to claim 6, characterized in that: The mixing is first performed by hand milling and then by mixing; the mixing method adopted is mechanical ball milling, solvent-assisted ball milling or melt quenching; The process parameters of the mechanical ball milling method are: The ball milling beads have a diameter of 3~10 mm, the material-ball ratio is (60:1)~(20:1), the ball milling time is 1~30 h, and the ball mill speed is 400~800 r / min.

8. The method for preparing a solid electrolyte material according to claim 6, wherein: The types of solid electrolyte materials include positive electrode side solid electrolyte materials, negative electrode side solid electrolyte materials and intermediate layer region solid electrolyte materials; When the positive electrode side solid electrolyte material is used, the auxiliary component used as the functional additive is a positive electrode stabilizer selected from one or more of LiF, LiTFSI, TiF4 and AlF3; When it is a solid electrolyte material on the negative electrode side, the auxiliary component used as a functional additive is one or more of LiF, LiNO3, Li3N, LiFSI, LiTFSI and Li2S; When the solid electrolyte material is used in the intermediate layer region, the auxiliary component used as a functional additive is one or more of Li2O, Li3PO4, Li4SiO4, and Li2CO3; or no auxiliary component used as a functional additive is added; The inert atmosphere is in an anhydrous and oxygen-free environment.

9. A battery comprising the solid electrolyte material according to any one of claims 1 to 5, wherein the battery comprises a positive electrode sheet, a negative electrode sheet, and a solid electrolyte layer located between the positive electrode sheet and the negative electrode sheet; The solid electrolyte layer is obtained by pressing the solid electrolyte material according to any one of claims 1 to 5.

10. The battery according to claim 9, wherein the positive electrode sheet is obtained by cold pressing or coating a positive electrode active material and a positive electrode filler; The positive electrode active material includes at least one of cobalt aluminum oxide, lithium iron phosphate, lithium-rich lithium manganese oxide, lithiated layered oxide and lithiated layered sulfide; The positive electrode filler is at least one of an ion conductor, a conductive agent, and an adhesive; the ion conductor is the same as the solid electrolyte material between the positive electrode sheet and the negative electrode of the battery; the conductive agent is at least one of graphite, carbon black, acetylene black, Ketjen black, and carbon fiber; the adhesive is at least one of styrene-butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene; The negative electrode sheet is obtained by cold pressing or coating a negative electrode active material and a negative electrode filler; the negative electrode active material is a material capable of storing and releasing Al ions; the negative electrode filler is at least one of an ion conductor, a conductive agent, and a binder; the ion conductor is the same as the solid electrolyte material between the positive and negative electrode sheets of the battery; the conductive agent is at least one of graphite, carbon black, acetylene black, Ketjen black, and carbon fiber; the binder is at least one of styrene-butadiene rubber, polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene; The pressing method is cold pressing.

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