Sulfide-based lithium ion conductive solid material and its manufacturing method

Abstract

The present invention relates to solid materials obtained by melt-quenching mixtures of lithium sulfide, boron sulfide, boron oxide, and Se, Te, In, or combinations thereof, thereby forming glassy solids that are suitable for use in, for example, lithium ion and electrochemical cells as conductive coatings and that exhibit great thermal stability.

Description

[Technical Field]

[0001] The present invention relates to a solid material obtainable by melt-quenching a mixture of lithium sulfide, boron sulfide, and boron oxide, thereby forming a glassy solid suitable for use as a conductive coating, for example, an electrode coating. The present invention further relates to a method for preparing said solid material, an electrochemical cell such as a solid-state battery comprising said solid material, and the use of the solid material in an electrochemical cell such as a solid-state battery, in particular an electrode coating. [Background technology]

[0002] The three main functional components of a lithium-ion battery are the negative electrode, the positive electrode, and the electrolyte. Although many variations exist, the negative electrode of a conventional lithium-ion cell is typically made from carbon, the positive electrode is typically made from a transition metal oxide (particularly an oxide of cobalt, nickel, and / or manganese), and the electrolyte is typically a non-aqueous solvent containing a lithium salt. For example, a mixture of an organic carbonate and lithium hexafluorophosphate is a well-known liquid electrolyte for lithium-ion batteries.

[0003] A significant drawback of liquid electrolytes is that their compositions, particularly the solvents, are flammable, which poses a significant safety risk during normal operation and especially in the event of an accident. Another drawback, inherent in the liquid nature of the electrolyte, is related to the increased risk of leakage and environmental contamination in the event of a leak.

[0004] In recent years, efforts have been made to develop solid-state electrolytes that can provide solid-state lithium-ion batteries. Such solid-state batteries significantly reduce EHS (environment, health, and safety) hazards. An emerging class of lithium-ion conducting solid electrolytes are sulfide-based amorphous solids (interchangeably referred to as glassy solids), such as Li2S-SiS2, Li2S-P2S5, or Li2S-B2S3.

[0005] A major challenge in the fabrication of glassy solid electrolytes is to avoid crystalline regions in the solid material. x The thermal stability of a material is determined by the onset of crystallization (Tx) and the glass transition temperature (T g ), i.e., ΔT x =T x -T g The larger the ΔT, the more stable the crystallization. x But generally, It is associated with improved glass forming ability and enhanced glass stability during post-processing.

[0006] Another key issue in the development of solid-state batteries with improved energy density and safety profiles is the degradation of cell performance resulting from interfacial reactivity and the resulting resistance buildup between electrodes, particularly the cathode and the solid-state electrolyte (SSE). The interfacial layer formed between the cathode active material (CAM) and the SSE impedes the transfer of Li ions and electrons, resulting in significant capacity fade and poor C-rate performance. This interfacial instability is one of the main issues limiting the commercialization of all-solid-state batteries (ASSBs).

[0007] To mitigate the interfacial resistance between the CAM and SSE and the resulting degradation of cell performance, a buffer layer is often applied to prevent direct contact between the CAM and the electrolyte. In principle, either the electrode or the electrolyte could be coated to stabilize the electrode / electrolyte interface. Because the positive electrode is where ionic conductivity is converted to electronic conductivity, it is important that such a coating have sufficient electronic conductivity to prevent inhibition of positive electrode function.

[0008] Initial studies on Li2S-B2S3 compositions with molar ratios of 70:30 and 60:40 showed Δ Tx values ​​were reported (Zhang et al, Solid State Ionics 1990, 38, 217-224).

[0009] WO 2016 / 089899 contemplates numerous glass systems, many of which are speculative or unsupported. Paragraphs 186 and 188 of WO 2016 / 089899 state that ΔT x Paragraph 190 of WO 2016 / 089899 suggests the addition of oxygen to improve ΔT above 100°C. x We speculate that it may have the following.

[0010] WO 2020 / 254314 proposes sulfide-based lithium ion conducting solid electrolytes of the Li2S-B2S3 type obtained from mixtures further containing P, Si, Ge, As, or Sb oxides in combination with lithium halides. The resulting glassy solids are said to have favorable lithium ion conductivity, as well as electrochemical stability in direct contact with lithium metal and chemical stability to air and moisture. The ΔT of these solids is x is in the range of 5 to 36°C (Table 3 of WO 2020 / 254314). Summary of the Invention [Problem to be solved by the invention]

[0011] A drawback with most sulfide-based lithium ion conducting glasses known in the art is that they do not provide good conductivity or high ΔT x Therefore, there is currently a great need to provide a sulfide-based lithium-ion conducting solid electrolyte that combines both properties.

[0012] Currently, there is a great need to provide improved electrolyte or electrode coating materials, particularly electrode coating materials that have limited chemical reactivity with both the electrolyte and the electrode, and that exhibit reasonable lithium ion conductivity and sufficient electronic conductivity.

[0013] It is an object of the present invention to provide an improved sulfide-based lithium ion conducting material that can be used as an electrolyte or an electrode coating, in particular as an electrode coating, and that exhibits high ionic and electronic conductivity. Tx、 In particular, Δ Tx The object of the present invention is to provide such an electrolyte or coating material having the following structure: [Means for solving the problem]

[0014] The inventors have discovered that one or more of the objects of the present invention can be achieved by providing a sulfide-based lithium ion conductive solid coating obtained by melt-quenching a combination of Li2S, B2S3, BO3, and X in well-defined ratios, where X represents Se, Te, In, or a combination thereof. As shown in the accompanying examples, the resulting glassy solid exhibits enhanced thermal stability, ΔT, relative to Li-S based glasses. x , high ionic conductivity, and / or high electrical conductivity.

[0015] Thus, in a first aspect of the invention, there is provided a solid material M having a composition according to general formula (I), Li 2c B 2a+2b S 3a+c O 3b X d (I) wherein X represents Se, Te, In, or a combination thereof; a is in the range of 0.04 to 0.12, b is in the range of 0 to 0.04; c is in the range of 0.12 to 0.26; A solid material M is provided in which d is in the range of 0.001 to 0.17.

[0016] In another aspect of the present invention, a solid material N is obtained by melt quenching a mixture of A and B, the molar ratio of A to B in the mixture before quenching is in the range of 60:40 to 99:1; Component A is according to general formula (II): xLi2S-yB2S3-zB2O3(II) During the ceremony, x is in the range of 55 to 85, preferably in the range of 55 to 75, More preferably, it is in the range of 60 to 70. y is in the range of 15 to 45, preferably in the range of 20 to 40, more preferably in the range of 25 to 35; z is in the range of 0 to 15, preferably in the range of 0 to 10, more preferably in the range of 0 to 6, and even more preferably in the range of 0 to 5; x+y+z=100, A solid material N is provided, wherein component B is selected from Se, Te, In, or a combination thereof.

[0017] In another aspect of the invention, there is provided a method for preparing a solid material, the method comprising the steps of: (i) providing a precursor of: Li2S, B2S3, and / or both boron and sulfur, optionally, B2O3, and providing X, wherein X represents Se, Te, In, or a combination thereof; (ii) preparing a mixture comprising the precursor provided in step (i), in said mixture, the molar ratios of the elements Li, S, B, O, and X conform to general formula (I), Li 2c B 2a+2b S 3a+c O 3b X d (I) During the ceremony, a is in the range of 0.04 to 0.12, b is in the range of 0 to 0.04; c is in the range of 0.12 to 0.26; d is in the range of 0.001 to 0.17, More preferably, a is in the range of 0.06 to 0.11, b is in the range of 0 to 0.04; c is in the range of 0.13 to 0.19, d is in the range of 0.002 to 0.07, preferably in the range of 0.002 to 0.03; or In the mixture, the molar ratio of precursors conforms to general formula (II): xLi2S-yB2S3-zB2O3(II) During the ceremony, x is in the range of 55 to 85, preferably in the range of 55 to 75, more preferably in the range of 60 to 70; y is in the range of 15 to 45, preferably in the range of 20 to 40, more preferably in the range of 25 to 35; z is in the range of 0 to 15, preferably in the range of 0 to 10, more preferably in the range of 0 to 6, and even more preferably in the range of 0 to 5; x+y+z=100, adjusting the mixture, wherein component A is according to general formula (II), component B is selected from Se, Te, In, or a combination thereof, and the molar ratio of A and B is within a range of 60:40 to 99.5:0.5; (iii) heat treating the mixture prepared in step (ii) to obtain a melt; (iv) quenching the melt obtained in step (iii) to obtain a solid material.

[0018] In another aspect of the present invention, there is provided a solid composition comprising a first solid material, which is solid material M and / or N as described herein, and further comprising at least a second solid material having a different composition than the first solid material.

[0019] In another aspect of the present invention, there is provided an electrochemical cell comprising the solid-state material described herein.

[0020] In another aspect of the present invention, there is provided the use of the solid material M and / or N described herein, or the solid composition described herein, as a solid electrolyte for an electrochemical cell or as a coating for an electrochemical cell component, for example, as an electrode, or as a coating for an electrolyte material.

[0021] Another aspect of the present invention relates to batteries, more particularly to at least one electrochemical cell comprising the solid-state material M and / or N described herein, e.g., a lithium-ion battery, or a lithium metal battery or a lithium solid-state battery, comprising two or more electrochemical cells described herein.

[0022] A further aspect of the present invention is a method of making or operating stationary applications such as automobiles, computers, personal digital assistants, cell phones, watches, camcorders, digital cameras, thermometers, calculators, laptop BIOS, communications equipment, satellites, remote car locks, and energy storage devices for power plants by employing at least one battery or at least one electrochemical cell comprising the solid-state materials described herein.

[0023] A further aspect of the present disclosure is the use of an electrochemical cell comprising the solid-state material of the present invention in an automobile, a bicycle powered by an electric motor, a robot, an aircraft (e.g., an unmanned aerial vehicle including a drone), a ship, a satellite, or a stationary energy storage station.

[0024] In another aspect of the present invention, the use of Se, Te, In, or a combination thereof, Thermal stability of glassy solids ΔT x In particular, the thermal stability ΔT of sulfide-based lithium ion conductive solid electrolytes or coatings is improved. x to improve, or To improve the ionic and / or electronic conductivity of sulfide-based lithium ion conductive solid electrolytes or coatings, The use of glassy solids, in particular sulfide-based amorphous solids such as Li2S-SiS2, Li2S-P2S5 or Li2S-B2S3, is provided. DETAILED DESCRIPTION OF THE INVENTION

[0025] In the following detailed description, preferred embodiments are described in detail to enable the practice of the invention. While the invention is described with reference to these specific preferred embodiments, it will be understood that the invention is not limited to these preferred embodiments. On the contrary, the invention includes numerous alternatives, modifications, and equivalents which will become apparent in view of the following detailed description and the accompanying drawings.

[0026] The glass transition temperature (T g ) refers to the onset temperature of the glass transition as measured by differential scanning calorimetry (DSC). It is preferably determined by constructing tangents to the DSC curve baseline before and after the glass transition and determining the extrapolated onset temperature by the intersection of these tangents, which essentially corresponds to the temperature at which the highest slope in the drop in the DSC baseline occurs before the exothermic crystallization peak. DSC is preferably recorded using a temperature profile from 100°C to 350°C at a rate of 10°C / min, preferably on a 5-10 mg sample in a sealed aluminum pan. A suitable DSC instrument is the DSC3500 Sirius.

[0027] The thermal stability (Δ Tx ) is the crystallization onset temperature (T x ) and the glass transition temperature (T g ) In other words, ΔT x =T x -T gAs explained in the previous paragraph, the glass transition temperature (T g ) refers to the onset temperature of the glass transition as measured by differential scanning calorimetry (DSC).

[0028] Ionic conductivity referred to herein refers to ionic conductivity determined by electrochemical impedance spectroscopy (EIS) at 25°C. It is preferably determined with an ion-blocking electrode on hot-pressed samples densified at 350 MPa for 5 minutes at 125°C, after which ionic conductivity was measured at 25°C under an operating pressure of 125 MPa. Preferably, an excitation voltage of 10 mV was applied in the frequency range of 7 MHz to 1 Hz, and data was interpreted by equivalent circuit analysis. A suitable conductivity analyzer is a potentiometer with a frequency analyzer, such as those available from Biologic.

[0029] Electronic conductivity referred to herein refers to electronic conductivity determined at 25°C. It is preferably determined with an ion-blocking electrode on hot-pressed samples densified at 350 MPa for 5 minutes at 125°C, after which electronic conductivity was measured at 25°C under an operating pressure of 125 MPa. Preferably, electronic conductivity was measured via stepped potential polarization at 0.2, 0.4, and 0.6 V for 20 minutes. A suitable conductivity analyzer is a potentiometer with a frequency analyzer, such as those available from Biologic.

[0030] References herein to Se, Te, or In relate to the elements Se, Te, or In. The inventors have found that when the elemental forms of these materials are mixed with the glass-forming components LiS, B2S3, and B2O3, this results in materials of the present invention that have certain improved properties (as described throughout this application), which differ from, for example, the properties obtained when oxides of these materials are used.

[0031] In a first aspect of the invention, there is provided a solid material M having a composition according to general formula (I), Li 2cB 2a+2b S 3a+c O 3b X d (I) wherein X represents Se, Te, In, or a combination thereof; a is in the range of 0.04 to 0.12, b is in the range of 0 to 0.04; c is in the range of 0.12 to 0.26; A solid material M is provided in which d is in the range of 0.001 to 0.17.

[0032] Without wishing to be bound by any theory, the inventors believe that a solid material M according to formula (I) is the result obtained upon melt quenching a mixture of LiS, BS, BO, and X, where X represents Se, Te, In, or combinations thereof, in the context of other aspects of the invention and as described herein in the Examples.

[0033] A solid material M having a composition according to general formula (I), wherein: a is in the range of 0.04 to 0.12, b is in the range of 0 to 0.04; c is in the range of 0.12 to 0.21; d is in the range of 0.001 to 0.17, More preferably, a is in the range of 0.06 to 0.11, b is in the range of 0 to 0.04; c is in the range of 0.13 to 0.19, d is in the range of 0.002 to 0.07, preferably in the range of 0.002 to 0.03; More preferably, a is in the range of 0.06 to 0.10, b is in the range of 0.002 to 0.02, preferably in the range of 0.005 to 0.02; c is in the range of 0.13 to 0.19, A solid material M is preferably provided in which d is in the range of 0.002 to 0.07, preferably in the range of 0.002 to 0.03.

[0034] Generally, d is within the range of 0.002 to 0.06, preferably within the range of 0.002 to 0.03, more preferably within the range of 0.01 to 0.03, and most preferably within the range of 0.011 to 0.023.

[0035] In each of the embodiments of compositions according to general formula (I) described herein, the molar ratio may be calculated so that the sum of 5a+5b+3c+d is in the range of 0.9 to 1.1, preferably in the range of 0.99 to 1.01, and most preferably about 1.

[0036] A solid material M having a composition according to general formula (I), for example when prepared by melt quenching, may be accompanied by a small amount of an impurity phase, which typically consists mainly of the precursors used to prepare the solid or intermediate formed from said precursors.

[0037] In a second aspect of the present invention, there is provided a solid material N obtained by melt quenching a mixture of A and B, the molar ratio of A to B in the mixture before quenching is in the range of 60:40 to 99:1; Component A is represented by general formula (II): xLi2S-yB2S3-zB2O3(II) During the ceremony, x is in the range of 55 to 85, preferably in the range of 55 to 75; More preferably, it is in the range of 60 to 70. y is in the range of 15 to 45, preferably in the range of 20 to 40, more preferably in the range of 25 to 35; z is in the range of 0 to 15, preferably in the range of 0 to 10, more preferably in the range of 0 to 6, and even more preferably in the range of 0 to 5; x+y+z=100, A solid material N is provided, wherein component B is selected from Se, Te, In, or a combination thereof.

[0038] In a preferred embodiment of the present invention, the solid material N is obtained by melt-quenching a mixture of A and B, x is in the range of 62 to 68, preferably in the range of 63 to 67, more preferably in the range of 64 to 66; y is in the range of 27 to 33, preferably in the range of 28 to 32, and more preferably in the range of 29 to 31; z is in the range of 1 to 8, preferably in the range of 3 to 7, more preferably in the range of 4 to 7, and even more preferably in the range of 4 to 6; x+y+z=100.

[0039] According to a highly preferred embodiment of the present invention, a solid material N is obtained by melt quenching a mixture of A and B, x is about 65; y is about 30; A solid material N is provided, where z is about 5.

[0040] Generally, the molar ratio of A to B in the mixture before quenching is within the range of 72:25 to 98:2, preferably within the range of 80:20 to 98:2, more preferably within the range of 85:15 to 96:4, and most preferably within the range of 90:10 to 96:4. Most preferably, the molar ratio of A to B in the mixture before quenching is within the range of 92:8 to 98:2, for example, 92:8 to 96:4.

[0041] Thus, in some embodiments of the present invention, a solid material N is obtained by melt quenching a mixture of A and B, wherein: x is in the range of 62 to 68, preferably in the range of 63 to 67, more preferably in the range of 64 to 66; y is in the range of 27 to 33, preferably in the range of 28 to 32, and more preferably in the range of 29 to 31; z is in the range of 1 to 8, preferably in the range of 3 to 7, more preferably in the range of 4 to 6; x+y+z=100, The molar ratio of A to B in the mixture before quenching is within the range of 75:25 to 98:2, preferably within the range of 80:20 to 98:2, more preferably within the range of 85:15 to 96:4, and most preferably within the range of 90:10 to 96:4, to provide a solid material N. Most preferably, the molar ratio of A to B in the mixture before quenching is within the range of 92:8 to 98:2, for example, 92:8 to 96:4.

[0042] In some embodiments of the present invention, a solid material N is obtained by melt-quenching a mixture of A and B, x is about 65; y is about 30; z is about 5; x+y+z=100, A solid material N is provided in which the molar ratio of A and B in the mixture before quenching is within the range of 75:25 to 98:2, preferably within the range of 80:20 to 98:2, more preferably within the range of 85:15 to 96:4, most preferably within the range of 90:10 to 96:4, and most preferably within the range of about 95:5.

[0043] Without wishing to be bound by any theory, it is generally believed therefore that in some preferred embodiments of the present invention, the solid material N obtained by melt quenching a mixture of A and B described herein is a solid material having a composition according to general formula (I) described herein.

[0044] The solid materials N according to different aspects of the invention described herein, i.e., the solid materials having a composition according to general formula (I) described herein, and the solid materials obtained by melt-quenching a mixture of A and B described herein (i.e., the solid material of embodiment 2), are collectively referred to as "solid materials."

[0045] According to preferred embodiments of the present invention, solid materials N are provided, in which X represents Se. As shown in the accompanying examples, these materials exhibit high electronic and ionic conductivity and high thermal stability. In these embodiments, it is particularly preferred that the solid material N of the present invention is a composition according to general formula (I) described herein, in which d is in the range of 0.008 to 0.01, preferably in the range of 0.01 to 0.03; or the solid material of the present invention is obtained by melt-quenching a mixture of A and B described herein, in which the molar ratio of A to B in the mixture before quenching is in the range of 85:15 to 96:4, most preferably in the range of 90:10 to 96:4.

[0046] According to preferred embodiments of the present invention, solid materials N are provided, in which X represents Te. As shown in the accompanying examples, these materials exhibit high ionic conductivity and high thermal stability. In these embodiments, it is particularly preferred that the solid material N of the present invention is a composition according to general formula (I) described herein, in which d is in the range of 0.008 to 0.01, preferably in the range of 0.01 to 0.03; or the solid material of the present invention is obtained by melt-quenching a mixture of A and B described herein, in which the molar ratio of A to B in the mixture before quenching is in the range of 85:15 to 96:4, most preferably in the range of 90:10 to 96:4.

[0047] The solid materials of the present invention are typically glassy solids and can be obtained by melt-quenching a mixture of precursors. In some embodiments, the solid material is in the form of a monolithic glass, such as a fusion-cast monolithic glass. Preferably, the glassy solid is essentially free of crystalline phases. In some embodiments, this can mean that the amount of crystalline phase is less than 5% by volume, preferably less than 2% by volume, and more preferably less than 1% by volume of the solid material, as measured by X-ray diffraction. A phase is considered crystalline if the intensity of its reflection is more than 10% higher than the background.

[0048] The solid-state material of the present invention has surprisingly been found to have high electronic conductivity, making it a very attractive material for coating solid-state battery components such as electrodes or electrolyte materials, especially electrode materials. According to a preferred embodiment of the present invention, a solid-state material is provided, the material having a high electrical conductivity of at least 5×10 at 25° C. -5 mS / cm, preferably at least 7×10 -5 As shown in the accompanying examples, the inventors have surprisingly found that when at least 50 mol % of X represents Se, preferably at least 80 mol % of X represents Se, and most preferably X represents Se, the electronic conductivity at 25° C. is 1.64×10 -4 Thus, in some embodiments of the present invention, a solid material is provided, the material having a viscosity of at least 5.61×10 mS / cm at 25° C. -5 mS / cm, preferably at least 7.9 x 10 -5 mS / cm, more preferably at least 1×10 -4 mS / cm, most preferably 1.5 x 10 -4 In a particular embodiment of the invention: at least 50 mol % of X represent Se, preferably at least 80 mol % of X represent Se, most preferably X represents Se; - The solid material has a viscosity of at least 5.61 x 10 at 25°C. -5 mS / cm, preferably at least 7.9 x 10 -5 mS / cm, more preferably at least 1×10 -4 mS / cm, most preferably 1.5 x 10 -4 It has an electronic conductivity of mS / cm.

[0049] For example, in some embodiments of the solid state material of the present invention, at least 80 mol % of X represents Se, and the electronic conductivity of the solid state material at 25° C. is at least 6.9×10 -5 mS / cm, or X represents Se and the electronic conductivity of the solid material at 25°C is at least 7.9 x 10 -5mS / cm, e.g., at least 1 × 10 -4 mS / cm, or at least 1.5 × 10 -4 mS / cm.

[0050] It has been found that the solid materials M and / or N of the present invention combine said high electronic conductivity with a high ionic conductivity. According to a preferred embodiment of the present invention, a solid material is provided, which has an ionic conductivity of more than 0.1 mS / cm at 25° C., preferably more than 0.25 mS / cm, and an ionic conductivity of at least 5×10 at 25° C. -5 mS / cm, preferably at least 7×10 -5 As shown in the accompanying examples, the inventors have surprisingly found that X is When Se is used, the electronic conductivity at 25°C is 1×10 -4 >mS / cm or 1.5 x 10 -4 It has been found that the ionic conductivity may be very high, such as greater than 1×10 mS / cm at 25° C. Thus, in some embodiments of the present invention, a solid material is provided, the material having an ionic conductivity of greater than 0.1 mS / cm at 25° C., preferably greater than 0.25 mS / cm, and an ionic conductivity of greater than 1×10 mS / cm at 25° C. -4 mS / cm, preferably greater than 1.5 x 10 -4 In certain embodiments of the invention: at least 50 mol % of X represent Se, preferably at least 80 mol % of X represent Se, most preferably X represents Se; the solid material has an ionic conductivity of greater than 0.1 mS / cm at 25°C; - The solid material has a viscosity of 1 x 10 at 25°C. -4 mS / cm, preferably greater than 1.5 x 10 -4 It has an electronic conductivity of more than mS / cm.

[0051] As shown in the accompanying examples, the glassy solids of the present invention have extremely high thermal stability ΔT xAccording to a preferred embodiment of the present invention, a solid material M and / or N is provided, the material having a thermal stability ΔT of greater than 100°C, preferably greater than 110°C, more preferably greater than 115°C. x In some embodiments, particularly when X represents Se, Te, or a combination thereof, the thermal stability ΔT x is above 120°C.

[0052] In a particularly highly preferred embodiment, the solid materials M and / or N of the invention are provided the solid material has an ionic conductivity at 25°C of at least 0.1 mS / cm, preferably at least 0.3 mS / cm, the solid material has a thermal stability ΔT of more than 100°C, preferably more than 110°C, more preferably more than 115°C x and Preferably, the solid material has a pH of 1×10 at 25°C. -4 mS / cm or more, preferably 1.5×10 -4 It has an electronic conductivity of more than mS / cm.

[0053] As described throughout this application, the solid materials M and / or N of the present invention can be obtained by melting and quenching a mixture of precursors to obtain a glassy solid. In some applications, it may be preferable for the material to be provided in the form of a particulate solid, such as a powder. This may facilitate blending with the positive electrode material, for example. The solid may be obtained directly in the form of a particulate solid (such as a powder) or may be comminuted (by milling, grinding, etc.) into a particulate solid (such as a powder). In other applications, it may be preferable for the solid material to be provided in the form of a thin sheet or film, preferably having a thickness of less than 500 microns, preferably less than 100 microns.

[0054] The inventors contemplate adding small amounts of other materials during synthesis in such a way that the general formula (I) of the resulting solid material M is no longer respected, or that the general formula (II) of the resulting material N is no longer respected, but the changes do not substantially affect the basic and novel property(ies) of the solid materials of the invention. Such modifications, which are in fact impurities, are considered to be within the scope of general formula (I) or (II) for purposes of the present invention.

[0055] In a third aspect of the present invention, there is provided a method for preparing a solid material, comprising the steps of: (i) providing a precursor of: Li2S, B2S3, and / or both boron and sulfur, optionally, B2O3, and providing X, wherein X represents Se, Te, In, or a combination thereof; (ii) (ii) preparing a mixture comprising the precursor provided in step (i), in said mixture, the molar ratios of the elements Li, S, B, O, and X conform to general formula (I), Li 2c B 2a+2b S 3a+c O 3d X d (I) a is in the range of 0.04 to 0.12, b is in the range of 0 to 0.04; c is in the range of 0.12 to 0.26; d is in the range of 0.001 to 0.17, or In the mixture, the molar ratio of precursors conforms to general formula (II): xLi2S-yB2S3-zB2O3(II) During the ceremony, x is in the range of 55 to 85, y is in the range of 15 to 45, z is in the range of 0 to 15, x+y+z=100, adjusting the mixture, wherein component A is according to general formula (II), component B is selected from Se, Te, In, or a combination thereof, and the molar ratio of A and B is within a range of 60:40 to 99.5:0.5; (iii) heat treating the mixture prepared in step (ii) to obtain a melt; (iv) quenching the melt obtained in step (iii) to obtain a solid material.

[0056] This method is generally referred to as the melt-quench method of the present invention. This process is cost-effective and easily scalable. Preferred embodiments of general formula (I), particularly a, b, c, and d, described herein in the context of the materials of the present invention, are equally applicable to the method of preparing solid material M. Similarly, preferred embodiments of general formula (II), particularly x, y, and z, described herein in the context of the second aspect of the present invention, are equally applicable to the melt-quench method of the present invention for preparing solid material N. Furthermore, preferred embodiments of the solid materials of the present invention (i.e., of the first and second aspects of the present invention) are generally equally applicable (e.g., with respect to the identity of X, with respect to conductivity, thermal stability, etc.) to the melt-quench method of the third aspect of the present invention.

[0057] Preferably, the mixture in step (ii) is a mixture of A and B, where component A is according to general formula (II) and component B is selected from Se, Te, In, or a combination thereof, and the ratio of A to B in the mixture before quenching is within the range of 60:40 to 99:1, and the molar ratio of A to B in the mixture before quenching is within the range of 72:25 to 98:2, preferably within the range of 80:20 to 98:2, more preferably within the range of 85:15 to 96:4, and most preferably within the range of 90:10 to 96:4. Most preferably, the molar ratio of A to B in the mixture before quenching is within the range of 92:8 to 98:2, for example, 92:8 to 96:4.

[0058] The provision of both boron and sulfur in step (i) should be interpreted as meaning the provision of elemental boron and elemental sulfur. The elemental boron and elemental sulfur may be provided in amorphous or crystalline form, and the particular allotropes used are not particularly limited to the present invention.

[0059] Preparing the mixture of step (ii) may be carried out by any suitable means, preferably by mechanical milling (eg ball milling).

[0060] Step (iii) comprises heating the mixture prepared in step (ii) to obtain a melt, i.e., heat treating at a temperature above the melting temperature of the mixture prepared in step (ii). Step (iii) preferably comprises heat treating the mixture prepared in step (ii) at a temperature of at least 400° C., preferably at least 600° C., more preferably at least 800° C. The mixture is preferably kept at this temperature for at least 15 minutes, preferably at least 30 minutes, more preferably at least 2 hours.

[0061] The heat treatment may be carried out in a closed vessel, which may be a sealed quartz tube or any other type of vessel that can withstand the temperature of the heat treatment and that does not undergo reaction with the components of the glass, such as a closed vessel made from a material selected from magnesium oxide, boron nitride, copper, tungsten, silicon nitride, aluminum nitride, carbon, and combinations thereof. The heat treatment of step (iii) may be a single-stage or multi-stage heat treatment.

[0062] Step (iii) is preferably carried out under an inert gas atmosphere, preferably an inert atmosphere comprising one or more noble gases (such as argon), and / or at a pressure of less than 1 atmosphere, preferably less than 0.1 atmosphere, more preferably less than 0.01 atmosphere. Typically, therefore, step (iii) is carried out under an inert gas atmosphere, preferably less than 10 atmospheres, more preferably less than 0.1 atmospheres, more preferably less than 0.01 atmospheres. -4 less than atmospheric pressure, preferably 10-5 It is preferably carried out at less than atmospheric pressure, preferably under an inert gas atmosphere, preferably an inert atmosphere containing one or more noble gases (such as argon). The use of nitrogen as an inert atmosphere should generally be avoided due to potential reactions with the glass precursor.

[0063] It is highly preferred that the melt quenching method of the present invention is for the preparation of the solid materials described herein.

[0064] In some embodiments of the melt quenching method of the present invention, (iv) comprises the steps of: (iv)a quenching the melt obtained in step (iii) to obtain a solid material; (iv)b. grinding the solid material of step (iv) to obtain a particulate solid, such as a powder; (iv)c Optionally, forming a thin film or sheet, preferably having a thickness of less than 500 microns, preferably less than 100 microns, - forming by dissolving or suspending the particulate solid of step (iv)b in a liquid phase to obtain a solution or suspension, followed by deposition from the solution or suspension to obtain a thin film or sheet; or - forming the particulate solid of step (iv)b by reheating to a temperature sufficient to allow for stretching and stretching of said film or sheet.

[0065] In an alternative embodiment, step p(iv) comprises quenching the melt of step (iii) while maintaining a temperature high enough to allow stretching of the thin film or sheet, and stretching said film or sheet, preferably stretching a film or sheet having a thickness of less than 500 microns, preferably less than 100 microns.

[0066] The method is preferably operated as a continuous process to produce continuous glass film, or sheet, which is cut to the desired size.

[0067] The quenching step in step (iv) is preferably carried out by contacting the melt obtained in step (iii) directly or while the container is closed or open (preferably while closed) with water, ice, optionally cooled gas (e.g. air), optionally cooled metal plates (e.g. roller quench), and / or a chemically inert mould.

[0068] In another aspect of the present invention, there is provided a solid composition comprising a first solid material, the first solid material being a solid material described herein, and further comprising at least a second solid material having a different composition than the first solid material.

[0069] The first solid material may be present in the form of discrete particles embedded within a matrix of the second solid material, or the first and second solid materials may be present in the form of discrete particles blended, optionally in combination with a binder material and one or more additional materials, and the blend is preferably compressed.

[0070] Alternatively, the first solid material and / or the second solid material may be present in the form of different layers of a multi-layer thin sheet or film, preferably having a total thickness of less than 500 microns, preferably less than 200 microns. It is highly preferred that the first solid material (a solid material described herein) is coated on the second solid material. This is particularly useful when the second solid material is an electrochemical cell component, such as a solid electrolyte or an electrode (particularly a positive electrode).

[0071] In another aspect of the present invention, there is provided an electrochemical cell comprising the solid-state material described herein.

[0072] In particular, electrochemical cells are provided in which the positive electrode, negative electrode, separator, and / or coating thereof comprise a solid-state material as defined herein. In particularly preferred embodiments of the present invention, electrochemical cells are provided in which the solid-state material of the present invention is provided in the form of a coating, particularly a coating on an electrode material such as a positive electrode material. In some embodiments, the separator consists of a solid-state material as described herein.

[0073] In another aspect of the present invention, there is provided the use of the solid material described herein, or the solid composition described herein, as a solid electrolyte for an electrochemical cell or as a coating for an electrochemical cell component, for example, as a coating for an electrode or electrolyte material, and in particular as a coating for an electrode material.

[0074] In the context of the various embodiments of the invention described herein, suitable electrochemically active positive electrode materials and suitable electrochemically active negative electrode materials are known in the art. For example, the negative electrode can include graphitic carbon, metallic lithium, or a metal alloy containing lithium as the negative electrode active material. For example, the positive electrode can include nickel-cobalt or nickel-manganese-cobalt positive electrode materials. The electrochemical cells described herein are preferably lithium-ion containing cells, and charge transport is achieved by Li + The electrochemical cell may be affected by ions. The electrochemical cell may have a disk-like or prismatic shape. The electrochemical cell may include a housing, which may be made of steel or aluminum. Multiple electrochemical cells may be combined into an all-solid-state battery having both solid electrodes and a solid electrolyte.

[0075] Another aspect of the present invention relates to batteries, and more particularly to at least one electrochemical cell comprising the solid-state materials described herein, e.g., a lithium-ion battery, or a lithium metal battery, or a lithium solid-state battery, comprising two or more electrochemical cells described herein.

[0076] The electrochemical cells described herein can be combined with one another, for example, in series or parallel connections. Series connections are preferred. Each battery of the electrochemical cells described herein can be used to create or operate stationary applications such as automobiles, computers, personal digital assistants, cell phones, watches, camcorders, digital cameras, thermometers, calculators, laptop BIOS, communications equipment, satellite or remote car locks, and energy storage devices for power plants.

[0077] A further aspect of the present invention is a method of making or operating stationary applications such as automobiles, computers, personal digital assistants, cell phones, watches, camcorders, digital cameras, thermometers, calculators, laptop BIOS, communications equipment, satellites, remote car locks, and energy storage devices for power plants by employing at least one battery or at least one electrochemical cell comprising the solid-state materials described herein.

[0078] A further aspect of the present disclosure is the use of an electrochemical cell comprising the solid-state material of the present invention in an automobile, a bicycle powered by an electric motor, a robot, an aircraft (e.g., an unmanned aerial vehicle including a drone), a satellite, a ship, or a stationary energy storage station.

[0079] The present invention further provides a device comprising at least one electrochemical cell as described herein. Preferably, the device is a mobile device, such as a vehicle, e.g., a car, a bicycle, an aircraft, a satellite, or a watercraft, such as a boat or a ship. Other examples of mobile devices are portable, e.g., a computer, in particular a laptop, a phone, or a power tool, e.g., from the construction sector, in particular a drill, a battery-powered screwdriver, or a battery-powered tacker.

[0080] In another aspect of the present invention, the use of Se, Te, In, or a combination thereof, Thermal stability of glassy solids ΔT xIn particular, the thermal stability Δ of the sulfide-based lithium ion conductive solid electrolyte or coating, preferably the coating, is improved. Tx To improve Use of a sulfide-based lithium ion conducting solid electrolyte or coating, preferably a coating, for improving ionic and / or electronic conductivity.

[0081] Without wishing to be bound by any theory, the inventors believe that the use of the materials described herein as positive electrode coatings improves electrochemical stability, chemical stability, lithium ion mobility, and general performance and lifetime (such as tested via long-term cycling performance) when utilized in electrochemical cells.

[0082] [Example] 1. Material Preparation For each example, 15 g of final material was produced using starting products of amorphous B2S3 (99 wt%), Li2S (99.9 wt%), and B2O3 (99.95 wt%), and X (detailed in the table below). In an argon-filled glove box, appropriate amounts of starting materials were weighed, mixed, and introduced into a carbon-coated silica ampoule. The tube was sealed and introduced into a vertical rocking furnace. The melt was homogenized at an internal temperature of 950 °C for 30 minutes and then quenched in water at room temperature. The ampoule was then opened in the argon-filled glove box. A glassy material with a yellow, orange, or brown color with good transparency was obtained.

[0083] 2.Thermal stability ΔT x Decision Thermal analysis was performed using a differential scanning calorimetry DSC 3500 Sirius. 5-10 mg samples of glassy material were placed in sealed aluminum pans and analyzed using the following temperature profile: 100 °C to 350 °C at a rate of 10 °C / min. For each sample, the glass transition temperature (T g ), and the onset of crystallization (T x ) was determined. Thermal stability was then calculated as the simple difference between those values ​​(ΔTx =T x -T g ) was estimated.

[0084] Glass transition temperature (T g ) is determined by constructing tangents to the DSC curve baseline before and after the glass transition, and the intersection of these tangents determines the extrapolated onset temperature, where the highest slope of the DSC baseline decline essentially corresponds to the temperature occurring before the exothermic crystallization peak. The T determined in this way g The starting temperature is T g It was used as.

[0085] 3. Conductivity Determination Ionic conductivity was measured by electrochemical impedance spectroscopy (EIS) at room temperature (25°C) on hot-pressed samples in a pellet cell with an ion-blocking electrode. The samples were densified at 350 MPa for 5 minutes at 125°C. Ionic conductivity was measured under an operating pressure of 125 MPa. For EIS, an excitation voltage of 10 mV was applied in the frequency range of 7 MHz to 1 Hz. Data were interpreted by equivalent circuit analysis.

[0086] Electronic conductivity was measured on hot-pressed samples in a pellet cell with an ion-blocking electrode at room temperature (25°C). The samples were densified at 350 MPa for 5 minutes at 125°C. Electronic conductivity was measured under an operating pressure of 125 MPa. Electronic conductivity was measured via stepped potential polarization at 0.2, 0.4, and 0.6 V for 20 minutes.

[0087] Both measurements were carried out potentiometrically using a frequency analyzer (Biologic).

[0088] [Table 1]

[0089] [Table 2]

[0090] As can be seen from Table 2, when Examples 2 and 6 according to the invention are compared with Comparative Example 1, which is not according to the invention, increased thermal stability, increased ionic conductivity, and / or decreased electronic conductivity were advantageously obtained. Furthermore, as can be seen from Table 2, thermal stability increases from In to Se to Te. Higher ionic conductivity was achieved at higher A:B ratios. Electronic conductivity decreases from Te to Se to In.

Claims

1. A solid material having a composition according to general formula (I), Li ２ｃ B ２ａ＋２ｂ S ３ａ＋ｃ O ３ｂ X ｄ (I) wherein X represents Se, Te, In, or a combination thereof; a is in the range of 0.04 to 0.12; b is in the range of 0 to 0.04; c is in the range of 0.12 to 0.26; A solid material wherein d is in the range of 0.001 to 0.

17.

2. a is in the range of 0.04 to 0.12; b is in the range of 0 to 0.04; c is in the range of 0.12 to 0.21; 2. The solid material of claim 1, wherein d is in the range of 0.001 to 0.

17.

3. a is in the range of 0.06 to 0.11; b is in the range of 0 to 0.04; c is in the range of 0.13 to 0.19; 2. The solid material according to claim 1, wherein d is in the range of 0.002 to 0.07, preferably in the range of 0.002 to 0.

03.

4. a is in the range of 0.06 to 0.10; b is in the range of 0.002 to 0.02, preferably in the range of 0.005 to 0.02; c is in the range of 0.13 to 0.19; 2. The solid material according to claim 1, wherein d is in the range of 0.002 to 0.07, preferably in the range of 0.002 to 0.

03.

5. 2. The solid material according to claim 1, wherein d is in the range of 0.002 to 0.06, preferably in the range of 0.002 to 0.03, more preferably in the range of 0.01 to 0.

03.

6. 2. The solid material of claim 1, wherein X is Se and d is in the range of 0.008 to 0.01, preferably in the range of 0.01 to 0.

03.

7. 2. The solid material of claim 1, wherein 5a+5b+3c+d=1.

8. The melt-quenched mixture of A and B is obtained by melt-quenching, and the molar ratio of A and B in the mixture before quenching is within the range of 60:40 to 99.5:0.5; Component A is represented by general formula (II): xLi ２ S-yB ２ S ３ -zB ２ O ３ (II) During the ceremony, x is in the range of 55 to 85, preferably in the range of 55 to 75; More preferably, it is in the range of 60 to 70. y is in the range of 15 to 45, preferably in the range of 20 to 40, more preferably in the range of 25 to 35; z is in the range of 0 to 15, preferably in the range of 0 to 10, more preferably in the range of 0 to 6, and even more preferably in the range of 0 to 5; x+y+z=100, 10. A solid material, preferably according to claim 1, wherein component B is selected from Se, Te, In, or a combination thereof.

9. x is in the range of 57 to 80, preferably in the range of 60 to 70, more preferably in the range of 65 to 70; y is in the range of 27 to 35, preferably in the range of 28 to 32, more preferably in the range of 29 to 31; z is in the range of 1 to 5, preferably in the range of 2 to 7, more preferably in the range of 4 to 7, even more preferably in the range of 4 to 6; 9. The solid state material of claim 8, wherein x+y+z=100.

10. 9. The solid material of claim 8, wherein the molar ratio of A and B in the mixture before quenching is in the range of 70:30 to 98:2, preferably in the range of 80:20 to 98:2, more preferably in the range of 85:15 to 96:4, most preferably in the range of 90:10 to 96:4, most preferably about 95:

5.

11. The solid material of claim 1 , wherein the material is a glassy solid.

12. 2. The solid material of claim 1, wherein the material has an ionic conductivity of at least 0.1 mS / cm at 25°C, preferably an ionic conductivity of at least 0.25 mS / cm, and a thermal stability above 110°C.

13. The material is at least 5×10 －５ mS / cm, preferably at least 7×10 －５ 10. The solid material of claim 1, having an electronic conductivity of mS / cm and a thermal stability of greater than 110°C.

14. A method for preparing a solid material, preferably as defined in any one of claims 1 to 13, comprising the following steps: (i) providing a precursor of: Li ２ S、 B ２ S ３ and / or both boron and sulfur, Optionally, B ２ O ３ , and providing X, where X represents Se, Te, In, or a combination thereof; (ii) preparing a mixture comprising the precursor provided in step (i), the molar ratio of the elements in the mixture corresponds to general formula (I) as defined in any one of claims 1 to 7, or preparing a mixture in which the molar ratio of the precursors conforms to general formula (II) as defined in any one of claims 8 to 10, and the molar ratio of A and B in the mixture is as defined in any one of claims 8 to 10; (iii) (iii) heat treating the mixture prepared in step (ii) to obtain a melt; (iv) (iv) quenching the melt obtained in step (iii) to obtain said solid material, preferably a solid material as defined in any one of claims 1 to 13.

15. Electrochemical cell comprising a solid-state material as defined in any one of claims 1 to 13.

16. Use of a solid material as defined in any one of claims 1 to 13 as a coating for an electrochemical cell component, preferably a cathode.

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