Modified solid electrolyte and its manufacturing method, solid-state battery and power consumption device

Abstract

The present application relates to a modified solid electrolyte, a method for manufacturing the same, a solid-state battery, and a power-consuming device, the modified solid electrolyte comprising a solid electrolyte substrate and a phase-change toughening agent distributed in the solid electrolyte substrate, the phase-change toughening agent being distributed mainly at grain boundaries in the solid electrolyte, and the phase-change toughening agent being capable of undergoing a phase change in response to the action of an external force. In one embodiment, the proportion of the number of particles of the phase-change toughening agent distributed at grain boundaries in the solid electrolyte to the total number of particles of the phase-change toughening agent in the modified solid electrolyte is ≧50%.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application references Chinese patent application No. 202310484801.9, filed on May 4, 2023, entitled "Modified solid electrolyte and manufacturing method thereof, solid-state battery and power consumption device," the entire contents of which are incorporated herein by reference.

[0002] This application relates to the field of battery technology, and in particular to modified solid electrolytes and methods for making same, solid-state batteries and power consuming devices. [Background technology]

[0003] In recent years, solid-state batteries manufactured using solid electrolytes have attracted increasing attention. On the one hand, solid-state batteries can avoid the flammability and explosion problems of liquid batteries due to the inclusion of organic electrolytes. On the other hand, solid-state batteries can use metals as anode materials, which can reduce the probability of side reactions occurring at high temperatures. Therefore, safety is considered one of the most fundamental driving forces behind the development of solid-state batteries. Furthermore, solid electrolytes give solid-state batteries features such as compact structure, scalability, and great design flexibility, which can be used to drive microelectronic devices and in the fields of power and energy storage.

[0004] Conventional solid electrolytes often have the brittle properties of ceramics, which means they have poor mechanical strength and are prone to cracking. They are prone to cracking during use. In particular, when combined with a lithium metal anode, the lithium metal forms dendrites at the solid electrolyte interface, which can cause the solid electrolyte to burst and even penetrate the solid electrolyte, resulting in a short circuit and failure of the solid-state battery, making it difficult to meet actual application needs.

[0005] Therefore, conventional techniques still need to be improved. Summary of the Invention [Means for solving the problem]

[0006] According to various embodiments of the present application, the present application provides a modified solid electrolyte, a manufacturing method thereof, a solid-state battery, and a power consumption device, which are intended to improve the toughness of the solid electrolyte and further improve the efficiency of the solid-state battery.

[0007] This application is realized by the following technical solutions:

[0008] According to a first aspect of the present application, there is provided a modified solid electrolyte, the modified solid electrolyte comprising: a solid electrolyte substrate; and a phase change toughening agent distributed in the solid electrolyte substrate; and in the modified solid electrolyte, the phase change toughening agent is distributed primarily at grain boundaries in the solid electrolyte; The phase change toughening agent is capable of undergoing a phase change upon application of an external force.

[0009] The modified solid electrolyte includes a solid electrolyte substrate and a phase change toughening agent distributed in the solid electrolyte substrate. When subjected to an external force, stress is generated inside the phase change toughening agent accordingly. The stress stimulates the phase change toughening agent to undergo a phase change. The stress transfer caused by this phase change process can improve the mechanical strength and toughness of the solid electrolyte substrate. The phase change toughening agent is mainly distributed along the grain boundary region in the modified solid electrolyte. The grain boundary is the defect region where cracks are most likely to occur when the solid electrolyte is subjected to external stress, and is also the region where dendrites are most likely to grow and spread. This can more accurately prevent the generation of internal defects in the solid electrolyte and further improve its toughness.

[0010] In some embodiments, the percentage of the number of particles of the phase change toughening agent distributed at the grain boundaries in the modified solid electrolyte relative to the total number of particles of the phase change toughening agent in the modified solid electrolyte is ≧50%.

[0011] In some of these embodiments, in the same cross-section of the modified solid electrolyte, if the total number of particles of the phase change toughening agent is N1 and the number of particles of the phase change toughening agent distributed at the grain boundaries in the same cross-section is N2, the degree of orientation of the phase change toughening agent distributed along the grain boundaries is A = N2 / N1×100%, and A satisfies A≧50%, Optionally, A satisfies 50% < A≦100%, Optionally, A satisfies 50% < A < 100%.

[0012] In the above modified solid electrolyte, on the same cross-section, if the degree of orientation of the phase change toughening agent distributed along the grain boundaries is H≧50%, in the modified solid electrolyte, it can be considered that the phase change toughening agent is mainly distributed along the grain boundaries in the modified solid electrolyte. Grain boundaries are the defect regions where cracks are most likely to occur when the solid electrolyte is subjected to external stress, and are also the regions where dendrites are most likely to grow and spread. Therefore, the phase change toughening agent is mainly distributed along the grain boundary regions in the modified solid electrolyte to more accurately avoid the occurrence of internal defects in the solid electrolyte and further improve the toughness.

[0013] In some of these embodiments, the same cross-section is the cross-section or longitudinal section of the modified solid electrolyte.

[0014] Specifically, the cross-section is a section formed by cutting perpendicularly to the height or thickness direction, and the longitudinal section is a section formed by cutting parallel to the height or thickness direction. For example, for a cylinder, its cross-section is a section formed by cutting perpendicularly to the height direction and is a circle, and its longitudinal section is a section formed by cutting parallel to the height direction and is a rectangle. The height of the cylinder is also called the thickness. When the height of the cylinder is relatively low, for example, when the height is smaller than the diameter of the ground, at this time, the cylinder is a wafer, and at this time, the general height is called the thickness.

[0015] In some of these embodiments, the test steps for the degree of orientation A are taking a sample of the modified solid electrolyte to be measured, cutting the sample along a direction perpendicular to the thickness of the wafer, and defining a cross section of the sample to be measured as a cross section to be measured; employing an X-ray energy spectrometer to mark the main elements contained in the phase change toughening agent in the cross-section to be measured, so that the main elements emit signal points, and acquiring a scanning electron microscope image of the cross-section to be measured; acquiring a total number M1 of the signal points in the scanning electron microscope image and a number M2 of the signal points contained in grain boundaries in the scanning electron microscope image; obtaining A based on M1 and M2; Specifically, A = M2 / M1 × 100%.

[0016] Here, the major element is an element that is contained in the phase change toughening agent but not contained in the solid electrolyte substrate.

[0017] In some of these embodiments, the phase change toughening agent comprises zirconium oxide and the predominant element is zirconium.

[0018] In some embodiments, the phase change toughening agent further comprises a stabilizer, and the mass proportion of the stabilizer in the phase change toughening agent is 0.01% to 50%; Optionally, the stabilizer contains at least one element selected from the group consisting of yttrium, scandium, magnesium, calcium, and cesium; Optionally, the stabilizer comprises at least one of yttrium oxide, scandium oxide, magnesium oxide, calcium oxide, and cesium oxide; Optionally, the stabilizer comprises yttrium oxide.

[0019] Although the specific toughening mechanism of phase change tougheners still needs further study, engineers speculate that phase change tougheners have a metastable state, i.e., they exist in a high-temperature stable crystalline structure at room temperature. Therefore, when subjected to external stress, phase change toughening materials undergo a phase change and volume change, which suppresses the breakdown of the solid electrolyte and achieves the phase change toughening effect. For example, when pure ZrO2 is cooled from a high temperature to room temperature, it typically undergoes a phase change from cubic (c), tetragonal (t) to monoclinic (m). At around 1150°C, the t to m phase change occurs, accompanied by a volume change of approximately 5%. If the t and m phase transition points of ZrO2 are stabilized at room temperature and an external stress is applied at room temperature to induce the tm phase transition, the volume effect generated by the phase change can absorb a large amount of fracture energy, resulting in the material exhibiting exceptionally high fracture toughness and achieving the phase change toughening effect.

[0020] In some embodiments thereof, the weight percentage of the phase change toughening agent in the modified solid electrolyte is 2% to 25%; Optionally, the mass percentage of the phase change toughening agent is 5% to 25%; Optionally, the mass percentage of the phase change toughening agent is 10% to 25%; Optionally, the weight percentage of the phase change toughening agent is 15% to 25%.

[0021] The weight percentage of the phase change toughener is adjusted to further improve the toughness of the modified solid electrolyte.

[0022] In some embodiments, the modified solid electrolyte has a mass m1 of the solid electrolyte substrate, a theoretical density ρ1 of the solid electrolyte substrate, a mass m2 of the phase change toughening agent, and a theoretical density ρ2 of the phase change toughening agent. The modified solid electrolyte has a theoretical volume Vt that satisfies Vt=[m1 / ρ1]+[m2 / ρ2]; When the true volume of the modified solid electrolyte is Vr, the density of the modified solid electrolyte is K=Vt / Vr×100%; Optionally, K satisfies K≧70%, and optionally, K satisfies 90%≦K≦100%.

[0023] It can be understood that the theoretical densities ρ1 and ρ2 are the densities of the pure solid electrolyte substrate and the pure phase change toughener, respectively, and can be understood as the densities of the solid electrolyte substrate material and the phase change toughener material used in manufacturing. Then, Vt represents the volume of the modified solid electrolyte. The larger the K value, the greater the difference between the actual volume and the theoretical volume, which means that the distribution inside the actual modified solid electrolyte is more compact and dense. When the modified solid electrolyte has a high density and is used in the manufacturing of solid-state batteries, defects and voids on the electrolyte sheet / membrane surface can be reduced, and the ionic conductivity of the modified solid electrolyte can be further improved.

[0024] In some embodiments, the solid electrolyte substrate includes one of a lithium ion solid electrolyte, a sodium ion solid electrolyte, and a potassium ion solid electrolyte.

[0025] According to a second aspect of the present application, there is provided a method for producing a modified solid electrolyte, the method comprising: mixing a solid electrolyte base material and a phase change toughening agent to form a mixture; and sintering the mixture under a protective gas atmosphere to produce the modified solid electrolyte.

[0026] In the above manufacturing method, during the sintering of the mixture, the crystal grains grow and the crystal grain boundaries fuse with each other. At the same time, the phase change toughener, which originally tends to be uniformly distributed in the mixture, is driven by the growth of the crystal grains, and most of the phase change toughener enters the crystal grain boundary region and is distributed along the crystal grain boundary orientation.

[0027] Furthermore, due to the effects of grain growth and grain boundary fusion, defects and voids in the modified solid electrolyte are significantly reduced, and the density is improved.

[0028] In some embodiments, the sintering process satisfies at least one of the following conditions (1) to (2): (1) The sintering temperature is 90°C to 600°C, and the sintering time is 10 minutes to 120 hours. By adjusting the temperature and time of the sintering process, the phase change toughener is driven by the grain growth, further promoting most of the phase change toughener to enter the grain boundary region, and ensuring the structural stability of the solid electrolyte substrate and the phase change toughener.

[0029] (2) The protective gas atmosphere is formed by filling the chamber with a protective gas containing at least one of an inert gas and nitrogen gas; Optionally, the protective gas is helium gas; Optionally, the protective gas has a moisture content of <0.1 ppm and an oxygen content of <0.1 ppm.

[0030] In some embodiments, the method further comprises, after the sintering process, pressing the product obtained by the sintering process; Optionally, the pressure T1 used in the pressing step satisfies T1≦400 MPa; Optionally, T1 satisfies 400 MPa≦T1≦600 MPa.

[0031] In some embodiments, the mixing step employs dry mixing, and before sintering the mixture, Further comprising a step of pressing the mixture into a sheet-like mixture, optionally the thickness of the sheet-like mixture is 200 μm to 2 mm, optionally the pressure used when pressing the mixture into a sheet-like mixture is 400 MPa to 600 MPa; or The mixing step employs wet mixing, and before sintering the mixture, The method further includes the step of applying the mixture and drying it to form a film-like mixture, and optionally, the film-like mixture has a thickness of 10 μm to 200 μm.

[0032] According to a third aspect of the present application, there is provided a solid state battery, the solid state battery comprising the modified solid electrolyte of the first aspect or the modified solid electrolyte obtained by the method for producing the modified solid electrolyte of the second aspect.

[0033] According to a fourth aspect of the present application, there is provided a power consuming device, said power consuming device comprising the solid-state battery of the third aspect. [Brief explanation of the drawings]

[0034] In order to more clearly explain the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used in the embodiments of the present application. It is obvious that the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on the drawings without any creative efforts. [Figure 1] FIG. 1 is a schematic diagram of a solid-state battery according to an embodiment. [Figure 2] FIG. 1 is a schematic diagram of one embodiment of a battery pack. [Figure 3] FIG. 3 is an exploded view of FIG. 2. [Figure 4] 1 is a schematic diagram of one embodiment of a power consuming device that uses a solid-state battery as a power source. [Figure 5] 1 is an electron microscope view of a cross section of the modified solid electrolyte prepared in Example 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0035] In order to make the above-mentioned objects, features and advantages of the present application more clearly understandable, the following detailed description of specific embodiments of the present application will be provided. In order to facilitate a thorough understanding of the present application, many specific details are set forth in the following description. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0036] In this application, unless otherwise clearly defined or limited, the terms "attached," "connected," "coupled," "fixed," etc. should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, internal communication between two elements, or an interactive relationship between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0037] It should be noted that the terms "first" and "second" are for descriptive purposes only and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of technical features indicated. A feature qualified as "first" or "second" may thereby explicitly or implicitly include at least one of said feature. In the description of this application, "plurality" means at least two, e.g., two, three, etc., unless otherwise clearly and specifically limited.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. Terms used herein in the specification of this application are for the purpose of describing specific examples only and are not intended to limit the scope of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0039] To summarize the above background, conventional solid electrolytes often have the brittle characteristics of ceramics. In the past, engineers have focused on the research and development of new solid electrolytes or the improvement of solid-state battery structures, but no significant breakthroughs or progress have been achieved so far.

[0040] According to research by the engineers of the present application, the contact interface formed when crystals of different orientations come into contact with each other in a solid electrolyte, i.e., the grain boundary, is a defect region where cracks are most likely to occur when the solid electrolyte is subjected to external stress, and is also a region where dendrites are most likely to grow and spread.

[0041] Based on this, the engineers of the present application have undergone a great deal of creative investigation and have obtained the modified solid electrolyte of the present application with excellent toughness.

[0042] One embodiment of the present application provides a modified solid electrolyte, the modified solid electrolyte including a solid electrolyte substrate and a phase change toughening agent distributed in the solid electrolyte substrate, and in the modified solid electrolyte, the phase change toughening agent is mainly distributed at grain boundaries in the modified solid electrolyte.

[0043] The phase change toughening agent is capable of undergoing a phase change upon application of an external force.

[0044] The modified solid electrolyte includes a solid electrolyte substrate and a phase change toughening agent distributed in the solid electrolyte substrate. When subjected to an external force, tensile stress is generated inside the solid electrolyte substrate. The tensile stress causes a phase change in the phase change toughening agent. The stress transfer caused by this phase change process can improve the mechanical strength and toughness of the solid electrolyte substrate. The phase change toughening agent is mainly distributed along the grain boundary region in the modified solid electrolyte. The grain boundary is the defect region where cracks are most likely to occur when the solid electrolyte is subjected to an external stress, and is also the region where dendrites are most likely to grow and spread. This can more accurately prevent the generation of internal defects in the solid electrolyte and improve its toughness.

[0045] It can be understood that the external force in the statement "the phase change toughening agent undergoes a phase change under the action of an external force" refers to the action exerted by the external environment other than the phase change toughening agent itself on the phase change toughening agent. Further, when the external force acts on the phase change toughening agent, it causes deformation of the phase change toughening agent, and internal forces that interact with each other further generate among the various parts within the phase change toughening agent. These internal forces resist the action of the external force and attempt to restore the phase change toughening agent from the deformed position to the position before deformation. Such internal forces are stress. Driven by the stress, a phase change occurs inside the phase change toughening agent, and by absorbing a large amount of fracture energy due to the volume change caused by the phase change, the effect of phase change toughening is achieved.

[0046] It can be understood that the grain boundary is the interface between grains with the same structure but different orientations. On the grain boundary interface, since the atomic arrangement transitions from one orientation to another, the atomic arrangement at the grain boundary is in a transitional state. When observed in the bright field of a scanning electron microscope (SEM), it can be seen that the grain boundary appears dark and black.

[0047] In some of these examples, among the total number of particles of the phase change toughening agent in the modified solid electrolyte, the proportion of the number of particles of the phase change toughening agent at the grain boundaries distributed in the solid electrolyte is ≥ 50%.

[0048] In some of these examples, in the same cross-section of the modified solid electrolyte, if the total number of particles of the phase change toughening agent is N1 and the number of particles of the phase change toughening agent distributed at the grain boundaries in the same cross-section is N2, the degree of orientation of the phase change toughening agent distributed along the grain boundaries is A = N2 / N1 × 100%, and A satisfies A ≥ 50%. Optionally, A satisfies 50% < A ≤ 100%. Optionally, A satisfies 50% < A < 100%.

[0049] In the above-mentioned modified solid electrolyte, on the same cross-section, if the degree of orientation of the phase change toughening agent distributed along the grain boundaries is A≥50%, in the modified solid electrolyte, it can be considered that the phase change toughening agent is mainly distributed along the grain boundaries in the modified solid electrolyte. Grain boundaries are the defect regions where cracks are most likely to occur when the solid electrolyte is subjected to external stress, and are also the regions where dendrites are most likely to grow and spread. Therefore, the phase change toughening agent is mainly distributed along the grain boundary regions in the modified solid electrolyte to more accurately avoid the occurrence of internal defects in the solid electrolyte and further improve the toughness.

[0050] It can be understood that the distribution situation of the phase change toughening agent in the entire modified solid electrolyte can be reflected from the distribution situation of the phase change toughening agent on the plane.

[0051] In the above-mentioned "50%<A≤100%", the value of A includes the minimum value and the maximum value in this range, and each value between such minimum value and maximum value. Specific examples include the point values in the examples and the following point values: 51%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, 100%, but are not limited thereto, or it is a range composed of any two numerical values. For example, 51% - 99%, 55% - 99%, 60% - 99%, 65% - 99%, 70% - 99%, 75% - 99%, 80% - 99%, 51% - 95%, 55% - 95%, 60% - 95%, 65% - 95%, 70% - 95%, 75% - 95%, 80% - 95%, 51% - 90%, 55% - 90%, 60% - 90%, 65% - 90%, 70% - 90%, 75% - 90%, 80% - 90%, 51% - 85%, 55% - 85%, 60% - 85%, 65% - 85%, 70% - 85%, 75% - 85%, 80% - 85%, 51% - 80%, 55% - 80%, 60% - 80%, 65% - 80%, 70% - 80%, 75% - 80%, 51% - 75%, 55% - 75%, 60% - 75%, 65% - 75%, 70% - 75%, 51% - 70%, 55% - 70%, 60% - 70%, 65% - 70% may also be possible.

[0052] In some embodiments, the same cross section is a cross section or a longitudinal section of the modified solid electrolyte.

[0053] Specifically, a cross section is a cross section formed by cutting perpendicular to the height or thickness direction, and a longitudinal section is a cross section formed by cutting parallel to the height or thickness direction, e.g., for a cylinder, its cross section is a cross section formed by cutting perpendicular to the height direction and is a circle, and its longitudinal section is a cross section formed by cutting parallel to the height direction and is a rectangle. The height of a cylinder is also called thickness, and when the height of the cylinder is relatively short, for example, when the height is smaller than the diameter of the ground, the cylinder is one wafer, and in this case the general height is called thickness.

[0054] Optionally, the same cross section is a cross section of the modified solid electrolyte. Still optionally, the modified solid electrolyte is a cylindrical body.

[0055] In some embodiments thereof, the step of testing the degree of orientation A includes: Taking a wafer of the modified solid electrolyte, cutting the wafer along a direction perpendicular to the thickness of the wafer, and setting the cut cross section formed when cutting the wafer as a cross section to be measured; employing an X-ray energy spectrometer to mark the major elements contained in the phase change toughening agent on the cross section to be measured, so that the major elements emit signal points, and acquiring a scanning electron microscope image of the cross section to be measured, wherein the major elements are elements contained in the phase change toughening agent but not contained in the solid electrolyte substrate; A step of acquiring a total number M1 of signal points in a scanning electron microscope image and a number M2 of signal points contained in grain boundaries in the scanning electron microscope image; and obtaining A based on M1 and M2.

[0056] Specifically, A = M2 / M1 × 100%.

[0057] It can be understood that the total number of signal points emitted from the main elements in the scanning electron microscope image can be counted, and this can be regarded as the total number of particles of the phase change toughening agent in the cross section to be measured; The number of signal points emitted from the main elements contained in the grain boundaries in the scanning electron microscope image can be counted, and this can be regarded as the number N2 of phase change toughening agent particles distributed in the grain boundaries in the cross section to be measured.

[0058] Specifically, in scanning electron microscope energy spectrum (SEM-EDS) analysis, an electron microscope is equipped with an EDS probe. For example, Zr is the main element. The Zr signal comes from the SEM's EDS probe. Its mechanism of action is to emit electrons to excite the surface material and detect the characteristic X-ray radiation. The scanning electron microscope image is divided into 1 μm square grids, and the number of Zr element signal points output by the EDS in the square grid is considered to be the number of particles of the phase change toughening agent.

[0059] Specifically, EDS scans were performed using an accelerating voltage of 10 kV, and the EDS probe was an Oxford Instrument AZtechOne.

[0060] Optionally, the thickness of the wafer is between 200 μm and 2 mm.

[0061] In some embodiments, when cutting the wafer perpendicular to the thickness of the wafer, the cutting point is located at half the thickness of the wafer.

[0062] In some of the embodiments, the magnification of the scanning electron microscope image is 1k to 5k.

[0063] In some embodiments, the region of the cross section to be measured is divided into n unit mesh regions, where n is an integer greater than or equal to 2, and each is placed under a scanning electron microscope for observation to form a scanning electron microscope image. The total number of signal points emitted from the main elements in the scanning electron microscope image of each mesh region and the number of signal points emitted from the main elements at the grain boundaries in the mesh region are counted, and the orientation degree An corresponding to each mesh region is calculated and averaged to obtain the orientation degree A of the cross section to be measured. A=(A1+….+An) / n.

[0064] In some embodiments, n satisfies 3≦n≦10, and n is an integer.

[0065] In some of these embodiments, n=5.

[0066] When n=5, the five-point sampling method is used for mesh division, and the mesh is divided into five mesh units. That is, the midpoint of the diagonal is first determined as the central sampling point mesh, and then four mesh units are selected on the diagonal that are equal to the central sampling point mesh distance.

[0067] Furthermore, when the above-mentioned cross-section to be measured is placed under a scanning electron microscope and observed, the position of the cross-section to be measured is changed multiple times and the above step is performed to obtain the orientation degrees of multiple regions of the cross-section to be measured, and then the average orientation degree of the multiple regions is calculated, which can be regarded as the orientation degree of the phase change toughening agent in the cross-section to be measured distributed along the crystal grain boundaries.

[0068] In some embodiments thereof, the phase change toughening agent comprises zirconium oxide, with the predominant element being zirconium.

[0069] In some embodiments, the phase change toughening agent further comprises a stabilizer, and the mass percentage of the stabilizer in the phase change toughening agent is 0.1% to 50%; Optionally, the stabilizer contains at least one of the elements yttrium, scandium, magnesium, calcium, and cesium.

[0070] In some embodiments thereof, the stabilizer component comprises an oxide.

[0071] Optionally, the stabilizer comprises at least one of yttrium oxide, scandium oxide, magnesium oxide, calcium oxide, and cesium oxide.

[0072] When the stabilizers are yttrium oxide, scandium oxide, magnesium oxide, calcium oxide, and cesium oxide, respectively, the toughening agents are YSZ, SSZ, MSZ, CSZ, and CsSZ, respectively.

[0073] Optionally, the stabilizer comprises yttrium oxide.

[0074] Although the specific toughening mechanism of phase change tougheners still needs further study, engineers speculate that phase change tougheners have a metastable state, i.e., they exist in a high-temperature stable crystalline structure at room temperature. Therefore, when subjected to external stress, phase change toughening materials undergo a phase change and volume change, which suppresses the breakdown of the solid electrolyte and achieves the phase change toughening effect. For example, when pure ZrO2 is cooled from a high temperature to room temperature, it typically undergoes a phase change from cubic (c), tetragonal (t) to monoclinic (m). At around 1150°C, the t to m phase change occurs, accompanied by a volume change of approximately 5%. If the t and m phase transition points of ZrO2 are stabilized at room temperature and an external stress is applied at room temperature to induce the tm phase transition, the volume effect generated by the phase change can absorb a large amount of fracture energy, resulting in the material exhibiting exceptionally high fracture toughness and achieving the phase change toughening effect.

[0075] In the above "0.01% to 50%", the value includes the minimum and maximum values ​​of this range, and each value between such minimum and maximum values. Specific examples include the point values ​​in the examples and the following point values: 0.01%, 0.05%, 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50%, but are not limited to these, or a range consisting of any two numbers, for example, 1% to 50%, 5% to 50%, 10% to 50%, 15% to 50%, 20% to 50%, 25% to 50%, 30% to 50%, 35% to 50%, 40% to 50%, 45% to 50%, 1% to 4 5%, 5%~45%, 10%~45%, 15%~45%, 20%~45%, 25%~45%, 30%~45%, 35%~45%, 40%~45%, 1%~40%, 5%~40%, 10%~40%, 15%~40%, 20%~40%, 25%~40%, 30%~40%, 35%~40%, 1%~3 It may be 5%, 5% to 35%, 10% to 35%, 15% to 35%, 20% to 35%, 25% to 35%, 30% to 35%, 1% to 30%, 5% to 30%, 10% to 30%, 15% to 30%, 20% to 30%, 1% to 25%, 5% to 25%, 10% to 25%, 15% to 25%, or 20% to 25%.

[0076] In some embodiments thereof, the weight percentage of the phase change toughening agent in the modified solid electrolyte is between 2% and 25%; In some embodiments, the weight percent of the phase change toughening agent is between 5% and 25%; In some embodiments, the weight percent of the phase change toughening agent is between 10% and 25%; In some of the embodiments, the weight percent of the phase change toughening agent is between 15% and 25%.

[0077] The weight percentage of the phase change toughener is adjusted to further improve the toughness of the modified solid electrolyte.

[0078] In the above "2% to 25%", the value includes the minimum and maximum values ​​of this range, and each value between such minimum and maximum values. Specific examples include, but are not limited to, the point values ​​in the examples and the following point values: 2%, 5%, 10%, 15%, 20%, and 25%, or a range consisting of any two numerical values, for example, 2% to 5%, 2% to 10%, 2% to 15%, 2% to 20%, 2% to 25%, 5% to 10%, 5% to 15%, 5% to 20%, 5% to 25%, 10% to 15%, 10% to 20%, 10% to 25%, 15% to 20%, 15% to 25%, and 20% to 25%.

[0079] In some embodiments, the modified solid electrolyte has a mass of the solid electrolyte substrate M1, a theoretical density ρ1, a mass of the phase change toughening agent M2, and a theoretical density ρ2, and the theoretical volume Vt of the modified solid electrolyte satisfies Vt=[M1 / ρ1]+[M2 / ρ2]; If the true volume of the modified solid electrolyte is Vr, the density of the modified solid electrolyte is K=Vt / Vr×100%. Optionally, K satisfies K≧70%, and optionally, K satisfies 90%≦K≦100%.

[0080] It can be understood that the theoretical densities ρ1 and ρ2 are the densities of the pure solid electrolyte substrate and the pure phase change toughener, respectively, and can be understood as the densities of the solid electrolyte substrate material and the phase change toughener material used in manufacturing. Then, Vt represents the volume of the modified solid electrolyte. The larger the K value, the greater the difference between the actual volume and the theoretical volume, which means that the distribution inside the actual modified solid electrolyte is more compact and dense. When the modified solid electrolyte has a high density and is used in the manufacturing of solid-state batteries, defects and voids on the electrolyte sheet / membrane surface can be reduced, and the ionic conductivity of the modified solid electrolyte can be further improved.

[0081] In some of these embodiments, the true volume Vr of the modified solid electrolyte is obtained by measuring the actual modified solid electrolyte with an Archimedes method or a micrometer.

[0082] In some of these embodiments, the solid electrolyte substrate includes any one of a lithium ion solid electrolyte, a sodium ion solid electrolyte, and a potassium ion solid electrolyte.

[0083] The lithium ion solid electrolyte, sodium ion solid electrolyte, and potassium ion solid electrolyte may be any of the various lithium ion solid electrolytes, sodium ion solid electrolytes, and potassium ion solid electrolytes commonly used in the art.

[0084] The solid electrolyte substrate in some of these embodiments is a lithium ion solid electrolyte.

[0085] Here, examples of the lithium ion solid electrolyte are described, including but not limited to the following: LISICON type: such as γ-Li3PO4, etc. NASICON type: such as Li (1+x1) Q x M (2-x1) (PO4)3, where 0 ≦ x1 < 1, and Q includes at least one of Al, Cr, Ba, Fe, Sc, In, Lu, Y, La. Garnet type: such as Li (7-x2) La3Zr (2-x2) M x2 O 12 etc., where 0 ≦ x2 < 1, and M includes at least one of Sb, Nb, Ta, Te, W. LIPON type: such as Li x3 PO y1 N z1 , where 0 < x3 ≦ 1, 0 < y1 ≦ 1, 0 < z1 ≦ 1. Perovskite type: such as Li3 x 4Q (2 / 3-x4) MO3 etc., where 0.04 < x4 < 0.17, Q includes at least one of La, Sr, Ba, Nd, and M includes at least one of Al, Ti, Ge. Anti-Perovskite type: such as Li3OCl, etc., Thio-LiSICON type: such as Li(3+x5) My2A (1-y2) Q (4-z2) T z2 Here, -1 < x5 < 2, 0 ≤ y2 ≤ 1, 0 ≤ z2 ≤ 2, M contains at least one of B, Al, In, Si, Ge, Sn, Ti, W, Mo, A contains at least one of P, As, Sb, Bi, Q contains at least one of S, Se, T contains at least one of F, Cl, Br, I, Sulfide solid electrolytes include Thiophosphate type: such as Li3PS4, Argyrodite type: Li6PS5Cl, Halide type: Li3InCl6, Hydride type: 0.7Li(CB9H 10 ) - 0.3Li(CB 11 H 12 ) and contain at least one of them. For example, Li (10+x6) M (1+y3) A (2-y3) Q (12-z3) H z3 type: Here, -2 < x6 < 2, 0 ≤ y3 ≤ 2, 0 ≤ z3 ≤ 2, M contains at least one of B, Al, In, Si, Ge, Sn, Ti, W, Mo, A contains at least one of P, As, Sb, Bi, Q contains at least one of S, Se, H contains at least one of F, Cl, Br, I: (100 - x7)Li2S·x7M·y4Q type: Here, 20 ≤ x7 ≤ 30, 0 ≤ y4 ≤ 50, M contains at least one of B2S3, Al2S3, In2S3, SiS2, GeS2, SnS2, P2S5, As2S3, Sb2S5, Bi2S3, WS2, MoS2, Q contains at least one of B2O3, Al2O3, In2O3, SiO2, GeO2, SnO2, P2O5, Sb2O5, Bi2O3, WO2, WO3, MoO2, MoO3, Fe2O3, ZnO, MgO, CuO, CaO, LiN, Li2O, LiF, LiCl, LiBr, LiI, Argyrodite type: Li (6+x8) M y5 A (1-y5) Q (5-z5) T (1+z5), where -1 ≤ x8 ≤ 1, 0 ≤ y5 ≤ 1, -1 < z5 ≤ 1, M contains at least one of B, Al, In, Si, Ge, Sn, Ti, W, Mo, A contains at least one of P, As, Sb, Bi, Q contains at least one of S, Se, T contains at least one of F, Cl, Br, I, and the Halide type: Li3MJ or Li2Sc 2 / 3 J and M contain at least one of Y, Er, In, Sc, Ga, and J contains at least one of F, Cl, Br, I.

[0086] When the above sulfide solid electrolyte is a sulfide-type solid electrolyte, it includes, but is not limited to, sulfur-silver-germanium electrolytes, binary sulfide-type solid systems such as Li2S-P2S5, Li2S-SiS2, Li2S-GeS, and Li2S-B2S3, and Li2S-Me-P2S5 ternary systems, where Me is selected from Si, Ge, Sn, Al, etc.

[0087] Specifically, the above sulfide electrolyte is selected from at least one of Li2S-P2S5, Li2S-SiS2, Li2S-GeS, Li2S-B2S3, and Li2S-Me-P2S5.

[0088] The sodium ion solid electrolyte includes, but is not limited to: NASICON type: Na (1+x9+2y5) Zr (2-y5) M y5 P (3-x9) Si x9 O 12 , where 0 ≤ x9 ≤ 3, 0 ≤ y5 ≤ 1, M contains at least one of Zn, Mg, Ca, and the Na-β-Alumina type: Na2O·2Al2O3 or Na2O·3Al2O3, etc., Na (3+x10) M y6 A (1-y6) Q (4-z6) T z6Type, where -1 < x10 < 2, 0 ≤ y6 ≤ 1, 0 ≤ z6 ≤ 2, M contains at least one of B, Al, In, Si, Ge, Sn, Ti, W, Mo, A contains at least one of P, As, Sb, Bi, Q contains at least one of S, Se, T contains at least one of F, Cl, Br, I, Na (11+x11) M (2-y7) A (1+y7) Q (12-z7) T z7 Type, where -1 < x11 < 1, 0 ≤ y7 ≤ 2, 0 ≤ z7 ≤ 2, M contains at least one of B, Al, In, Si, Ge, Sn, Ti, W, Mo, A contains at least one of P, As, Sb, Bi, Q = S, Se, T contains at least one of F, Cl, Br, I, perovskite - type Na3OX, X contains at least one of Cl, Br, I, BH4.

[0089] The potassium - ion solid electrolyte contains at least one of, but is not limited to, β - Alumina type (such as K2O·x13Al2O3, where x13 takes any one number from 8 to 11), Anti - Perovskite type (such as K3OI, etc.), K2Fe4O7 type, KSi2P3 type.

[0090] One embodiment of the present application further provides a method for manufacturing a modified solid electrolyte, including the following steps S10 to S20.

[0091] Step S10: Mix a solid electrolyte substrate and a phase - change toughening agent to produce a mixture.

[0092] Step S20: Sinter the mixture under a protective gas atmosphere to produce a modified solid electrolyte.

[0093] In the above manufacturing method, during the sintering period of the mixture, crystal grains grow and grain boundaries fuse with each other. At the same time, the phase - change toughening agent that originally tends to be uniformly distributed in the mixture is promoted by the growth of crystal grains, and most of the phase - change toughening agent enters the grain - boundary region and distributes along the grain - boundary orientation.

[0094] Furthermore, due to the effects of grain growth and grain boundary fusion, defects and voids in the modified solid electrolyte are significantly reduced, and the density is improved.

[0095] The types and further mass blending ratios of the solid electrolyte base material and the phase change toughening agent are as described above and will not be further described here.

[0096] In some of the examples, the sintering temperature is 90°C to 600°C, and the time is 10 minutes to 120 hours.

[0097] The temperature and time of the sintering process are adjusted to further encourage the phase change toughener to be driven by grain growth and most of the phase change toughener to enter the grain boundary region.

[0098] In some of the examples, the sintering temperature is between 90°C and 550°C.

[0099] Furthermore, the sintering temperature is adjusted to ensure that most of the phase change toughener enters the grain boundary region while maintaining the structural stability of the solid electrolyte substrate and the phase change toughener.

[0100] In the above "90°C to 600°C", the temperature value includes the minimum and maximum values ​​of this range, and each value between such minimum and maximum values. Specific examples include the point values ​​in the examples and the following point values: 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, 260°C, 270°C, 280°C. , 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, 390°C, 400°C, 410°C, 420°C, 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 570°C, 580°C, 590°C, 600°C, or a range consisting of any two numbers. For example, the temperature range is 100°C to 600°C, 100°C to 550°C, 100°C to 500°C, 100°C to 450°C, 100°C to 400°C, 100°C to 350°C, 100°C to 300°C, 100°C to 250°C, 100°C to 200°C, 150°C to 600°C, 150°C to 500°C, 150°C to 400°C, 150°C to 350°C, 150°C to 300°C, 150°C to 250°C, 150°C to 200°C, 200°C to 600°C, 200°C to 500°C , 200°C to 400°C, 200°C to 350°C, 200°C to 300°C, 200°C to 250°C, 250°C to 600°C, 250°C to 500°C, 250°C to 400°C, 250°C to 350°C, 250°C to 300°C, 300°C to 600°C, 300°C to 500°C, 300°C to 400°C, 300°C to 350°C, 400°C to 600°C, 400°C to 500°C, 450°C to 600°C, 450°C to 500°C, or 500°C to 600°C.

[0101] In the above "10 min to 120 h", the time value includes the minimum and maximum values ​​of this range, and each value between such minimum and maximum values. Specific examples include the point values ​​in the examples and the following point values: 110 h, 100 h, 95 h, 90 h, 85 h, 80 h, 75 h, 70 h, 65 h, 60 h, 55 h, 50 h, 45 h, 40 h, 35 h, 30 h, 25 h, 20 h, 15 h, 10 h, 9 h, 8 h, 7 h, 6 h, 5 h, 4 h, 3 h, 2 h, 1 h, 0.5 h, 20 min, 10 min, but are not limited thereto.

[0102] In some of the examples, in the sintering step S20, the temperature is increased to the sintering temperature at a rate of 10° C. / min.

[0103] It should be noted that the sintering process is timed from the time the temperature reaches the sintering temperature.

[0104] In some of the embodiments, the protective gas atmosphere is formed by filling a protective gas containing at least one of an inert gas and nitrogen gas.

[0105] Optionally, the protective gas is helium gas.

[0106] Optionally, the protective gas has a moisture content of <0.1 ppm and an oxygen content of <0.1 ppm.

[0107] In some embodiments, the method further comprises, after the sintering process, pressing the product obtained by the sintering process; Optionally, the pressure T1 used in the pressing step satisfies T1≦400 MPa; Optionally, T1 satisfies 400 MPa≦T1≦600 MPa.

[0108] Further pressing further tightens the component distribution of the modified solid electrolyte and also forces the phase change toughener into the grain boundary regions.

[0109] By further adjusting the pressure of the press, the degree of orientation A of the phase change toughening agent distributed along the grain boundaries can be further improved.

[0110] In some embodiments, the mixing step in step S10 is a dry mixing step, and before sintering the mixture, The method further includes pressing the mixture into a sheet of the mixture.

[0111] Optionally, the thickness of the sheet-like mixture is 200 μm to 2 mm.

[0112] In some of the examples, the pressure used to press the mixture into a sheet-like mixture is between 400 MPa and 600 MPa.

[0113] In some embodiments, the mixing step in step S10 is wet mixing, and before sintering the mixture, The method further includes the step of applying the mixture and drying it to form a film-like mixture, and optionally the thickness of the film-like mixture is 10 μm to 200 μm.

[0114] It can be understood that dry mixing refers to directly mixing a solid electrolyte base material with a phase change toughening agent, and wet mixing refers to mixing a solid electrolyte base material, a phase change toughening agent, a solvent, and an adhesive to form a mixture slurry.

[0115] Optionally, the solvent may be at least one of water, small molecule alcohol, benzene-based solvent, and alcohol ether-based solvent. Further, optional small molecule alcohols include ethanol, propanol, etc., and benzene-based solvents include toluene, xylene, etc.

[0116] The adhesive may be any adhesive commonly used in the art, including, but not limited to, at least one of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS), and polyvinylidene fluoride (PVDF).

[0117] Furthermore, the mixing is carried out under stirring, and the stirring method may be any stirring method commonly used in the art, such as using a ball mill for stirring, and the stirring time may be, but is not limited to, 0.5 hours to 6 hours, and the stirring rotation speed may be 100 rpm to 300 rpm.

[0118] The drying step is intended to dry the solvent in the wet film formed by coating. There are no particular requirements for the drying temperature or drying time, as long as the solvent in the wet film formed by coating can be volatilized and dried. Specifically, drying methods commonly used in this field can be adopted, including, but not limited to, vacuum drying and heat drying.

[0119] It should be noted that the solvent in the mixture after wet mixing volatilizes during the sintering process, and the adhesive carbonizes and forms gas during the sintering process, so the content of solvent and adhesive residue in the modified solid electrolyte produced after sintering is extremely small and can be almost ignored.

[0120] One embodiment of the present application provides a solid-state battery, which includes the modified solid electrolyte described above.

[0121] In the modified solid electrolyte, the phase change toughening agent is mainly distributed along the grain boundary region of the modified solid electrolyte. The grain boundary is the defect region where cracks are most likely to occur when the solid electrolyte is subjected to external stress, and is also the region where dendrites are most likely to grow and spread. Therefore, the phase change toughening agent can more accurately avoid the occurrence of internal defects in the solid electrolyte, improve the toughness, inhibit the dendrites from further penetrating the electrodes, and achieve high ionic conductivity, thereby improving the efficiency of the solid-state battery.

[0122] In some embodiments, the solid-state battery includes a modified solid electrolyte in the form of a diaphragm, and the solid-state battery further includes a positive electrode plate and a negative electrode plate, the modified solid electrolyte diaphragm being disposed between the positive electrode plate and the negative electrode plate.

[0123] The positive and negative electrode plates may be any positive and negative electrode plates commonly used in the art, and non-limiting examples of the positive and negative electrode plates will be described below.

[0124] Negative electrode plate The negative electrode plate includes a positive electrode current collector and a negative electrode active layer carried on the surface of the positive electrode current collector.

[0125] The components of the negative electrode active layer include a negative electrode active material.

[0126] The negative electrode active material may be any negative electrode active material commonly used in the present application, including at least one of a metallic lithium negative electrode material, a carbonaceous negative electrode material, an oxide negative electrode material, and a silicone-based negative electrode material.

[0127] In any embodiment of the present application, the negative electrode active material is selected from the group consisting of metallic lithium, lithium-containing alloys, lithium-containing composites, mesocarbon microbeads, graphite, glassy carbon, carbon nanotubes, carbon-carbon composites, carbon fibers, hard carbon, soft carbon, magnesium oxide, silicon carbon composites, TiO2, MoO2, In2O3, Al2O3, Cu2O, VO2, and SnO. x , SiO x, Ga2O3, Sb2O5, and Bi2O.

[0128] In any embodiment of the present application, the mass ratio of the negative electrode active material in the negative electrode active layer is 70% to 99.5%.

[0129] In any embodiment of the present application, the components of the negative electrode active layer further include a negative electrode conductive agent and a negative electrode adhesive.

[0130] In any embodiment of the present application, the negative electrode conductive agent may be a conductive material commonly used in the art, including, but not limited to, at least one of graphite, carbon nanotubes, nanofibers, carbon black, and graphene. Specifically, the negative electrode conductive agent may be selected from at least one of SP, KS-6, acetylene black, branched Ketjenblack ECP, SFG-6, vapor-grown carbon fiber VGCF, carbon nanotubes (CNTs) and graphene, and composite conductive agents thereof.

[0131] The weight ratio of the negative electrode conductive agent in the negative electrode active layer is 0 to 20 wt % based on the total weight of the negative electrode active layer.

[0132] The negative electrode adhesive may be an adhesive commonly used in the art, and may be selected from at least one of styrene butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), carboxymethyl chitosan (CMCS), and polyvinylidene fluoride (PVDF).

[0133] The weight ratio of the negative electrode adhesive in the negative electrode active layer is 0 to 30 wt % based on the total weight of the negative electrode active layer.

[0134] In any embodiment of the present application, the negative electrode active layer may further optionally contain other additives, such as a thickener, for example, carboxymethyl cellulose sodium (CMC-Na), etc. The weight ratio of the other additives in the negative electrode active layer is 0 to 15 wt %, based on the total weight of the negative electrode active layer.

[0135] In any embodiment of the present application, the current collector in the negative electrode plate may be a metal foil sheet or a composite current collector. For example, a copper foil may be used as the metal foil sheet. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer base layer. The composite current collector may be formed by forming a metal material (such as aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0136] In any embodiment of the present application, a negative electrode plate may be manufactured by the following method: the components for manufacturing a negative electrode plate, such as the negative electrode active material, conductive agent, adhesive, and optional other components, are dispersed in a solvent (e.g., deionized water) to form a negative electrode slurry. The negative electrode slurry is then coated onto a negative electrode current collector, followed by drying and cold pressing to obtain a negative electrode plate. Here, the solid content of the negative electrode slurry is 30 wt% to 70 wt%, and the viscosity at room temperature is adjusted to 2000 mPa·s to 10000 mPa·s. The resulting negative electrode slurry is then coated onto a negative electrode current collector, followed by drying and cold pressing, e.g., with a pair of rollers, to obtain a negative electrode plate. The unit areal density of the negative electrode powder coating is 75 mg / m 2 ~220mg / m 2 The compaction density of the negative electrode plate is 1.2 g / m 3 ~2.0g / m 3 is.

[0137] Positive electrode plate The positive electrode plate includes a positive electrode current collector and a positive electrode active layer carried on the surface of the positive electrode current collector.

[0138] The components of the positive electrode active layer include a positive electrode active material.

[0139] In some of the examples, the mass ratio of the positive electrode active material in the positive electrode active layer is 70% to 100%.

[0140] In some embodiments, the positive electrode active material may be any positive electrode active material for secondary batteries known in the art.

[0141] In any embodiment of the present application, the positive electrode active material includes one of a sodium ion positive electrode active material and a lithium ion positive electrode active material.

[0142] Further, as an example, the lithium ion active material may include at least one material selected from the group consisting of lithium-containing phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Here, examples of lithium transition metal oxides include lithium cobalt oxide (e.g., LiCoO), lithium nickel oxide (e.g., LiNiO), lithium manganese oxide (e.g., LiMnO, LiMnO), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (e.g., LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (may be abbreviated as NCM333), LiNi 0.5 Co 0.2 Mn 0.3 O2 (may be abbreviated as NCM523), LiNi 0.5 Co 0.25 Mn 0.25 O2 (may be abbreviated as NCM211), LiNi 0.6 Co 0.2 Mn 0.2 O2 (may be abbreviated as NCM622), LiNi 0.8 Co 0.1Mn 0.1 O2 (which may be abbreviated as NCM811), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.80 Co 0.15 Al 0.05 Examples of the lithium-containing phosphate having an olivine structure may include, but are not limited to, at least one of lithium iron phosphate (e.g., LiFePO4 (which may be abbreviated as LFP)), lithium manganese phosphate (e.g., LiMnPO4), and lithium manganese iron phosphate.

[0143] In any embodiment of the present application, the molecular formula of the lithium ion active material is LiFe x Mn (1-x) PO4, where x is any number between 0 and 1.

[0144] As can be understood, when x is 0, LiFe x Mn (1-x) PO4 is LiMnPO4 lithium manganese phosphate, and when x is 1, LiFePO4 is LiFePO4 lithium iron phosphate (LFP).

[0145] For example, the sodium ion positive electrode active material may include at least one of a sodium transition metal oxide, a polyanion-type compound, and a Prussian blue-based compound. However, the present application is not limited to these materials, and other conventionally known materials that can be used as positive electrode active materials for sodium ion batteries may also be used. In any embodiment of the present application, the positive electrode active material includes at least one of a sodium transition metal oxide, a polyanion-type compound, and a Prussian blue-based compound, Optionally, the positive electrode active material includes at least one of a sodium transition metal oxide and a polyanion-type compound.

[0146] Sodium transition metal oxides have a layered transition metal structure, and theoretically, the thickness rebound ratio of the layered transition metal structure is greater than that of the rhombohedral phase of Prussian blue-based compounds. However, in actual applications, Prussian blue-based compounds are prone to absorbing water, forming crystal water and vacancy defects, which increases the thickness rebound ratio and may even cause structural collapse. Therefore, when sodium transition metal oxides are used as the positive electrode active material, the thickness rebound ratio of the positive electrode plate is actually reduced.

[0147] The anionic structural units in the polyanionic compound are bonded to a three-dimensional structure by covalent bonds, which provides good structural stability, and when used as a positive electrode active material, the repulsion rate of the thickness of the positive electrode plate is relatively low.

[0148] As an optional technical solution of the present application, in the sodium transition metal oxide, the transition metal includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr and Ce. The sodium transition metal oxide is, for example, Na x MO2, where M comprises at least one or more of Ti, V, Mn, Co, Ni, Fe, Cr and Cu, and <x≦1である。

[0149] As an alternative technical solution of the present application, the polyanion type compound is a compound containing sodium ions, transition metal ions and tetrahedral (YO4) n- The transition metal may be one of compounds having an anionic unit, and the transition metal may include at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce, Y may include at least one of P, S, and Si, and n may be (YO4) n- represents the valence of

[0150] Polyanionic compounds include sodium ions, transition metal ions, and tetrahedral (YO4) n-The transition metal may be one of compounds having an anionic unit and a halogen anion, the transition metal may include at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce, Y may include at least one of P, S, and Si, and n may be (YO4) n- The halogen may be at least one of F, Cl, and Br.

[0151] Polyanionic compounds include sodium ions, tetrahedral (YO4) n- Anionic unit, polyhedral unit (ZO y ) m+ and may be a type of compound having an optional halogen anion. Y includes at least one of P, S, and Si, and n is (YO4) n- Z represents a transition metal, and includes at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce; m represents a valence of (ZO y ) m+ The halogen may be at least one of F, Cl, and Br.

[0152] Examples of polyanionic compounds include NaFePO4, Na3V2(PO4)3 (sodium vanadium phosphate, abbreviated as NVP), Na4Fe3(PO4)2(PO7), NaM'PO4F (where M' is one or more of V, Fe, Mn, and Ni), and Na3(VO y )2(PO4)2F 3-2y At least one of (0≦y≦1).

[0153] Prussian blue compounds contain sodium ions, transition metal ions, and cyanide ions (CN - The transition metal may be one of compounds having at least one of Mn, Fe, Ni, Co, Cr, Cu, Ti, Zn, V, Zr, and Ce. The Prussian blue compound may be, for example, Na a Me b Me' c(CN)6, wherein Me and Me' each independently contain at least one of Ni, Cu, Fe, Mn, Co, and Zn; <a≦2、0<b<1、0<c<1である。

[0154] In any embodiment of the present application, the components of the positive electrode active layer further include a positive electrode adhesive, and the mass ratio of the positive electrode adhesive in the positive electrode active layer is 0.05% to 10%.

[0155] Optionally, the mass ratio of the positive electrode adhesive in the positive electrode active layer is 0.1% to 8%.

[0156] The positive electrode adhesive may be any of various adhesives commonly used in the art, including, for example, at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, fluorine-containing acrylate resin, sodium carboxymethyl cellulose, hydroxypropyl cellulose, sodium hydroxymethyl cellulose, potassium hydroxymethyl cellulose, diacetyl cellulose, polyacrylic acid, sodium alginate, styrene-butadiene rubber, acrylate-butadiene rubber, polypyrrole, polyaniline, epoxy resin, and guado rubber.

[0157] In any embodiment of the present application, the components of the positive electrode active layer further include a positive electrode conductive agent, and the mass ratio of the positive electrode conductive agent in the positive electrode active layer is 0.05% to 8%.

[0158] Optionally, the mass ratio of the positive electrode conductive agent in the positive electrode active layer is 0.1% to 6%.

[0159] For example, the positive electrode conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0160] The positive electrode current collector may be a metal foil sheet or a composite current collector. For example, copper foil may be used as the metal foil sheet. The composite current collector may include a polymer base layer and a metal layer formed on at least one surface of the polymer substrate. The composite current collector may be formed by forming a metal material (such as copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, or silver alloy) on a polymer substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), or polyethylene (PE)).

[0161] In some embodiments, the positive electrode plate may be manufactured by the following method: the components for manufacturing the positive electrode plate, such as the positive electrode active material, the positive electrode conductive agent, the positive electrode adhesive, and any other components, are dispersed in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry, which is then coated onto a positive electrode current collector, and the positive electrode plate is obtained after processes such as drying and cold pressing.

[0162] In some embodiments thereof, the solid-state battery is a solid-state battery or a semi-solid-state battery.

[0163] In some embodiments, in a solid-state battery, the modified solid electrolyte is present in the form of a modified solid electrolyte diaphragm, positioned between positive and negative plates.

[0164] Additionally, the solid-state battery further includes a housing for enclosing the positive electrode plate, the negative electrode plate, and the modified solid electrolyte diaphragm.

[0165] In some embodiments, the housing may be a hard case, such as a hard plastic case, an aluminum case, or a steel case. Alternatively, the housing may be a pouch, such as a bag-shaped pouch. The pouch may be made of plastic, such as polypropylene, polybutylene terephthalate, or polybutylene succinate.

[0166] The present application does not particularly limit the shape of the battery, which may be cylindrical, rectangular, or any other shape. For example, Figure 1 shows an example of a rectangular solid-state battery 4.

[0167] The present application further provides a power consuming device, the power consuming device including the solid-state battery described above.

[0168] Furthermore, in the power consumption device, the solid-state battery may be in the form of a battery cell, or may be in the form assembled into a battery pack.

[0169] 2 and 3 show an example of a battery pack 1. The battery pack 1 includes a battery box and one or more solid-state batteries 4 installed in the battery box. The battery box includes an upper housing 2 and a lower housing 3, and the upper housing 2 is attached to the lower housing 3 as a lid, forming an airtight space for the batteries 4.

[0170] The plurality of solid-state batteries 4 may be arranged in the battery box in any manner.

[0171] The solid-state battery or its assembled battery pack may be used as a power source for a power consuming device, or as an energy storage unit for a power consuming device.

[0172] The power consuming devices may be, but are not limited to, mobile devices (e.g., mobile phones, laptops, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.

[0173] 4 shows an example of a power consumption device 5. The power consumption device 5 may be a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, etc. To meet the demand for high battery power and high energy density of the power consumption device 5, a battery pack format may be adopted.

[0174] Another example of a power consuming device may be a mobile phone, a tablet computer, a laptop computer, etc. These devices are generally required to be thin and may employ a battery as a power source.

[0175] The present application will be described below in conjunction with specific examples, but the present application is not limited to the following examples. It should be understood that the appended claims outline the scope of the present application, and those skilled in the art, guided by the concept of the present application, should recognize that certain modifications made to each example of the present application are all within the spirit and scope of the claims of the present application.

[0176] The following is a specific example.

[0177] Example 1 1. The specific steps of the preparation of modified solid electrolyte are as follows:

[0178] S1: Dry mixing of solid electrolyte base material (Li6PS5Cl) and phase change toughening agent: A Fritsch Pulverisette planetary ball mill was used to mix at a rotation speed of 100 rpm for 0.5 h to obtain a mixture.

[0179] The phase change toughener includes zirconium oxide and a stabilizer. The mass of the phase change toughener is used as the calculation basis, and the mass ratio of the stabilizer is Y1. The total mass of the mixture is used as the calculation basis, and the mass ratio of the phase change toughener is Y2. The specific parameters are as shown in Table 1.

[0180] S2: The mixture is poured into a mold and pressurized to a thickness of 1 mm and a surface area of ​​19.63 mm at a pressure of 500 MPa. 2 The mixture was pressed into a disk shape.

[0181] S3: The sheet-shaped mixture was placed in an argon gas environment (H2O<0.1ppm, O2<0.1ppm), heated to 350°C at a temperature increase rate of 10°C / min, kept at that temperature for 10 hours for sintering, and then cooled naturally to obtain a modified solid electrolyte.

[0182] S4: Performance test of modified solid electrolyte Examination of the orientation degree A of phase change tougheners distributed along grain boundaries in modified solid electrolytes: 1. The wafer was cut perpendicular to the thickness direction of the wafer, and the cutting point was located at 1 / 2 of the wafer thickness. The cut cross section formed when cutting the wafer was taken as the cross section to be measured.

[0183] 2. The cross-sectional area to be measured is divided into five unit mesh areas, each of which is placed under a scanning electron microscope for observation to form a scanning electron microscope image. The total number of signal points emitted by the main elements in the scanning electron microscope image of each mesh area is counted, which is regarded as the number of phase change toughener particles in each mesh area, and is designated as M11, M12, M13, M14, and M15, respectively. The number of signal points emitted by the main elements at the grain boundaries in each mesh area is counted, which is regarded as the number of phase change toughener particles at the grain boundaries in each mesh area, and is designated as M21, M22, M23, M24, and M25, respectively. The orientation degree of the phase change toughener distributed along the grain boundaries in the modified solid electrolyte in each mesh area is calculated, which is designated as A1, A2, A3, A4, and A5, respectively. The calculation method is as follows: A1 = M21 / M11 × 100%, A2 = M22 / M12 × 100%, A3=M23 / M13×100%, A4=M24 / M14×100%, A5=M25 / M15×100%, Then, the orientation degree A of the phase change toughener distributed along the grain boundaries in the modified solid electrolyte is calculated according to the following formula:

[0184] A=(A1+A2+A3+A4+A5) / 5 Here, when dividing into meshes, the five-point sampling method is referred to and the mesh is divided into five mesh units, that is, the midpoint of the diagonal is first determined as the central sampling point mesh, and then four mesh units equal to the central sampling point mesh distance on the diagonal are selected.

[0185] Specifically, each mesh region was analyzed using scanning electron microscope energy spectroscopy (SEM-EDS). The resulting scanning electron microscope image was divided into 1 μm square grids, and the number of Zr element signal points output from the EDS in the square grid was considered to represent the number of phase change toughening agent particles. The specific results are shown in Table 1. EDS scanning was performed using an accelerating voltage of 10 kV, and the EDS probe was an Oxford Instrument AZtechOne.

[0186] Here, a scanning electron microscope image of the measured cross section of the modified solid electrolyte is shown in Figure 5. As can be seen from the image, the phase change toughening agent particles are mainly concentrated and distributed along the electrolyte grain boundaries.

[0187] Fracture toughness testing of modified solid electrolytes: Fracture toughness is a parameter that describes the ability of a material to absorb strain energy before fracture occurs, and is expressed as the fracture toughness value (K ICThe higher the fracture toughness, the stronger the crack propagation inhibition ability, which also reflects the ability of the modified solid electrolyte to resist dendrite cleavage and short circuit. Fracture toughness can be measured using four-point bending tests, Vickers cone indentation tests, etc., and the Vickers cone indentation test is selected for measurement. The specific process is as follows:

[0188] The wafer surface of the modified solid electrolyte sheet was polished in an argon gas atmosphere with sandpaper, using 800 mesh, 2000 mesh, 4000 mesh, and 8000 mesh in that order, until the wafer surface exhibited a mirror-like finish without any obvious defects. An indentation test was then performed on the polished surface using a Vickers cone-type indentation tester. The indentation tester was driven with an appropriate load P until radial cracks appeared at the four corners of the cone-type indentation. The indentation load P, radial crack extension length C, and microhardness H obtained during the test were V Based on this, the fracture toughness value K IC Calculate

number

[0189] (3) Critical current density test of modified solid electrolyte The critical current density is the lowest current density at which dendrites and short circuits appear when electrochemical deposition occurs when a solid electrolyte material is combined with a corresponding alkali metal electrode. In other words, if the modified solid electrolyte is below the critical current density and electrochemical deposition occurs, dendrites and short circuits do not appear. The critical current density is a core indicator that describes the ability of a solid electrolyte material to suppress dendrites and short circuits.

[0190] The critical current density of the modified solid electrolyte is measured by cycling the current density stepwise in a conventional symmetrical battery. Specifically, taking a lithium ion solid electrolyte as an example, the process is as follows:

[0191] Two 50 μm-thick lithium metal wafers with 8 mm-long dendrites were placed on either side of the modified solid electrolyte wafer at symmetrical center positions, and mechanical pressure was used to bond the lithium metal wafers to the electrolyte sheet, forming a lithium / solid electrolyte / lithium symmetric battery. After assembly and packaging, the symmetric batteries were charged to 0.25 mA / cm. 2 Start with a current of 1 mAh / cm on one side 2 After lithium was deposited and peeled off, the current was applied at 0.5 mA / cm 2 and increased to 1mAh / cm 2 After deposition and peeling, the current was sequentially increased to 0.75 mA / cm. 2 , 1.0mA / cm 2 , 1.25mA / cm 2 ……10mA / cm 2 The voltage change during the process was monitored, and the current density at which the voltage suddenly dropped significantly was taken as the critical current density (Jc). The specific results are shown in Table 1.

[0192] (4) Ion conductivity test of modified solid electrolyte Ionic conductivity is a core index that measures the ability of a solid electrolyte to conduct corresponding metal ions. Ionic conductivity is generally tested by electrochemical AC impedance spectroscopy, and the corresponding ionic conductivity is calculated by the following process:

[0193] After plating a 200 nm thick nickel metal layer on both sides of the solid electrolyte wafer by magnetron sputtering PVD, a current collector was attached to the nickel metal layer and connected to the electrochemical workstation via a tab. The current collector was then heated at a bias voltage of 10 mV and a frequency of 10 6An electrochemical impedance test was performed on the solid electrolyte sheet under conditions of 0.1 Hz to 0.1 Hz. The Z' coordinate value of the point closest to the Z' axis from right to left in the low frequency band of the curve in the electrochemical impedance spectrum was taken as the resistance value R, and the ionic conductivity σ could be calculated using the following formula:

number

[0194] (5) Tests were conducted on the density of the modified solid electrolyte material, and the specific results are as follows:

[0195] 1. The mass of the solid electrolyte base material (Li6PS5Cl) used in the manufacturing process is m1, its theoretical density is ρ1, the mass of the phase change toughening agent is m2, and its theoretical density is ρ2. Calculate the theoretical volume Vt of the modified solid electrolyte according to the following formula: Vt=[m1 / ρ1]+[m2 / ρ2]; Here, m1 and m2 are both obtained by weighing on a balance, the solid electrolyte base material and the phase change toughening agent are both purchased products, and ρ1 and ρ2 are listed in the parameter table of the products.

[0196] 2. The true volume Vr of the modified solid electrolyte was obtained by Archimedes' method or measurement on the actual modified solid electrolyte.

[0197] 3. The density of the modified solid electrolyte is K=Vt / Vr, and the specific results are shown in Table 1.

[0198] S5: Solid-state battery manufacturing and performance testing (1) Manufacturing of positive electrode plates The positive electrode active material NCM811, the adhesive nitrile rubber (NBR), the conductive agent VGCF, and the electrolyte Li6PS5Cl were mixed in a mass ratio of 80:1.5:0.5:18, paraxylene was added, and the mixture was stirred to prepare a uniformly dispersed slurry. The slurry was evenly applied to one surface of an aluminum foil and transferred to a vacuum drying oven to completely dry. The resulting electrode plate was rolled and punched to obtain a positive electrode plate.

[0199] (2) Manufacturing of negative electrode plates The negative electrode plate is manufactured using lithium metal as the negative electrode active material as follows.

[0200] The lithium metal foil was rolled to a thickness of 50 μm, and then rolled again to coat the lithium metal foil on one surface of the copper foil, which was then slit to obtain a negative electrode plate.

[0201] The solid electrolyte membrane was placed between the negative and positive electrode plates, which were then laminated together to ensure intimate interfacial contact, forming a solid-state battery.

[0202] (3) Maximum charging current density test: The maximum charging current density of a solid-state battery can be measured by gradually increasing the current density cycle until failure. That is, after assembling and packaging the all-solid-state battery, the entire battery is charged at 0.25 mA / cm. 2 Then, charge and discharge the battery to a capacity of 1 mAh / cm 2 The current was controlled to 0.5 mA / cm to ensure a constant test surface capacitance during the cycle test, and was reduced to 0.5 mA / cm after the first cycle was completed. 2 and increased to 1mAh / cm 2 maintains a surface capacitance of 0.25 mA / cm after charge-discharge cycling. 2 with a gradient of 0.75 mA / cm 2 , 1.0mA / cm 2 , 1.25mA / cm 2 ……10mA / cm 2 The all-solid-state battery was cycled in this order, and the current density at which the voltage suddenly dropped significantly or obvious jitter appeared was determined as the maximum charging current density.

[0203] In reality, the maximum charging current density and the critical current density of the composite solid electrolyte have similar physical meanings, and the numerical values ​​of both are almost the same.

[0204] Example 2 Example 2 is basically the same as Example 1, and the only difference is that the type of stabilizer used in step S1 is different from that used in Example 1. The specific conditions are as shown in Table 1.

[0205] The other steps and conditions were the same as in Example 1, and the test results are shown in Table 1.

[0206] Examples 3 to 6 Examples 3 to 6 are basically the same as Example 1, with the only difference being that in step S1, the mass proportion Y2 of the phase-change toughening agent in the mixture is different from that in Example 1, and the specific conditions are as shown in Table 1.

[0207] The other steps and conditions were the same as in Example 1, and the test results are shown in Table 1.

[0208] Examples 7 to 13 Examples 7 to 13 are basically the same as Example 1, with the only difference being the temperature or time of the sintering treatment in step S3.

[0209] The other steps and conditions were the same as in Example 1, and the test results are shown in Table 1.

[0210] Examples 14 to 16 Examples 14 to 16 are basically the same as Example 1, with the only difference being that the mass proportion Y1 of the stabilizer in the phase-change toughening agent in step S1 is different from that in Example 1, and the specific conditions are as shown in Table 1.

[0211] The other steps and conditions were the same as in Example 1, and the test results are shown in Table 1.

[0212] Comparative Example 1 Comparative Example 1 is basically the same as Example 1, except that Comparative Example 1 directly provides the solid electrolyte substrate (Li6PS5Cl) to perform step S4 and subsequent steps.

[0213] Comparative Example 2 Comparative Example 2 was basically the same as Example 1, with the only difference being that step S3 was not performed in Comparative Example 2. Specific conditions were as shown in Table 1.

[0214] The remaining steps are the same as in Example 1.

[0215] The relevant physical parameters and test results in each example and comparative example are as shown in Table 1, where Y1 is the mass ratio of the stabilizer based on the mass of the phase change toughening agent, Y2 is the mass ratio of the phase change toughening agent based on the total mass of the modified solid electrolyte, A is the degree of orientation of the phase change toughening agent distributed along the grain boundaries in the modified solid electrolyte, and K, J, σ, and K are the fracture toughness, critical current density, ionic conductivity, and compactness of the modified solid electrolyte, respectively.

[0216] [Table 1-1] [Table 1-2] The note " / " indicates that there is no processing at this step or that this substance or parameter is not present.

[0217] As can be seen from the experimental results in the above table and the analytical comparison of the data of Example 1 and Comparative Examples 1 and 2, in the modified solid electrolyte of the present application, the phase change toughening agent is distributed mainly along the grain boundary region of the modified solid electrolyte. The grain boundary is the defect region where cracks are most likely to occur when the solid electrolyte is subjected to external stress, and is also the region where dendrites are most likely to grow and spread. Therefore, by distributing the phase change toughening agent mainly along the grain boundary region of the modified solid electrolyte, the occurrence of internal defects in the solid electrolyte can be more accurately avoided and the toughness can be further improved.

[0218] The technical features of the above-described embodiments can be combined in any manner, and for the sake of brevity, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered within the scope described in this specification.

[0219] The above examples merely represent several embodiments of the present application, and although the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the patent application should be determined based on the appended claims, and the specification and drawings can be used to interpret the content of the claims. [Explanation of symbols]

[0220] 1, battery pack, 2, upper housing, 3, lower housing, 4, solid-state battery, 5, power consumption device.

Claims

1. A modified solid electrolyte, the components of which include a solid electrolyte base material and a phase change toughening agent distributed in the solid electrolyte base material, and in which the phase change toughening agent is distributed primarily at grain boundaries in the solid electrolyte; The phase change toughening agent is a modified solid electrolyte capable of undergoing a phase change upon the action of an external force.

2. 2. The modified solid electrolyte of claim 1, wherein a percentage of the number of particles of the phase change toughening agent distributed at grain boundaries in the solid electrolyte out of a total number of particles of the phase change toughening agent in the modified solid electrolyte is ≧50%.

3. In the same cross section of the modified solid electrolyte, the total number of particles of the phase change toughening agent is N1, and the number of particles of the phase change toughening agent distributed at the grain boundaries in the same cross section is N2. The orientation degree of the phase change toughening agent distributed along the grain boundaries is A=N2 / N1×100%, and A satisfies A≧50%; Optionally, A satisfies 50%<A≦100%; Optionally, A satisfies 50%<A<100%.

4. 4. The modified solid electrolyte of claim 3, wherein the same cross section is a transverse or longitudinal cross section of the modified solid electrolyte.

5. The step of testing the degree of orientation A includes: taking a sample of the modified solid electrolyte to be measured, cutting the sample to be measured along a direction perpendicular to the thickness of the sample to be measured, and defining a cross section formed when cutting the sample to be measured as a cross section to be measured; employing an X-ray energy spectrometer to mark the major elements contained in the phase change toughening agent in the cross-section to be measured, so that the major elements emit signal points, and acquiring a scanning electron microscope image of the cross-section to be measured; acquiring a total number M1 of the signal points in the scanning electron microscope image and a number M2 of the signal points contained in grain boundaries in the scanning electron microscope image; and obtaining A based on M1 and M2; 4. The modified solid electrolyte of claim 3, wherein the major element is an element contained in the phase change toughening agent but not contained in the solid electrolyte substrate.

6. 6. The modified solid electrolyte of claim 5, wherein said phase change toughening agent comprises zirconium oxide and said predominant element is zirconium.

7. The phase change toughening agent further contains a stabilizer, and the mass proportion of the stabilizer in the phase change toughening agent is 0.01% to 50%; Optionally, the stabilizer contains at least one element selected from the group consisting of yttrium, scandium, magnesium, calcium, and cesium; Optionally, the stabilizer comprises at least one of yttrium oxide, scandium oxide, magnesium oxide, calcium oxide, and cesium oxide; 7. The modified solid electrolyte of claim 6, wherein optionally, said stabilizer comprises yttrium oxide.

8. In the modified solid electrolyte, the mass fraction of the phase change toughening agent is 2% to 25%; Optionally, the weight percentage of the phase change toughening agent is 5% to 25%; Optionally, the weight percentage of the phase change toughening agent is 10% to 25%; 8. The modified solid electrolyte of claim 1, wherein the weight percentage of the phase change toughening agent is between 15% and 25%.

9. In the modified solid electrolyte, when the mass of the solid electrolyte substrate is m1, the theoretical density is ρ1, the mass of the phase change toughening agent is m2, and the theoretical density is ρ2, the theoretical volume Vt of the modified solid electrolyte satisfies Vt = [m1 / ρ1] + [m2 / ρ2], When the true volume of the modified solid electrolyte is Vr, the density of the modified solid electrolyte is K=Vt / Vr×100%; 9. The modified solid electrolyte of claim 1, wherein K satisfies K≧70%, and wherein K satisfies 90%≦K≦100%.

10. 10. The modified solid electrolyte of claim 1, wherein the solid electrolyte substrate comprises one of a lithium ion solid electrolyte, a sodium ion solid electrolyte, and a potassium ion solid electrolyte.

11. A method for producing a modified solid electrolyte, comprising: mixing a solid electrolyte base material and a phase change toughening agent to form a mixture; and sintering the mixture under a protective gas atmosphere to produce a modified solid electrolyte.

12. The sintering process satisfies at least one of the following conditions (1) to (2): (1) The sintering temperature is 90°C to 600°C, and the sintering time is 10 minutes to 120 hours. (2) The protective gas atmosphere is formed by filling the chamber with a protective gas containing at least one of an inert gas and nitrogen gas; Optionally, the protective gas is helium gas; 12. The method for preparing a modified solid electrolyte according to claim 11, wherein optionally the protective gas has a moisture content of <0.1 ppm and an oxygen content of <0.1 ppm.

13. The method further comprises the step of pressing the product obtained by the sintering process after the sintering process; Optionally, the pressure T1 used in the pressing step satisfies T1≧400 MPa; Optionally, T1 satisfies 400 MPa≦T1≦600 MPa.

14. The mixing step employs dry mixing, and before sintering the mixture, Further comprising a step of pressing the mixture into a sheet-like mixture, optionally the thickness of the sheet-like mixture is 200 μm to 2 mm, and optionally the pressure used when pressing the mixture into a sheet-like mixture is 400 to 600 MPa; or The mixing step employs wet mixing, and before sintering the mixture, 13. The method for producing a modified solid electrolyte according to claim 11 or 12, further comprising the step of coating and drying the mixture to form a film-like mixture, and optionally, the thickness of the film-like mixture is 10 μm to 200 μm.

15. A solid state battery comprising the modified solid electrolyte according to any one of claims 1 to 10 or the modified solid electrolyte obtained by the method for producing the modified solid electrolyte according to any one of claims 11 to 14.

16. 16. A power consuming device comprising the solid state battery of claim 15.

Images