Cathode materials and methods of formation

Abstract

The cathode material can include a substrate including a cathode active material and a coating covering at least a portion of the substrate. The coating material can be CF X and M2CO3, where M can include an alkali metal. In certain embodiments, the coating can include MF. In another particular embodiment, M can include Li.

Description

[Technical Field]

[0001] The following relates to cathode materials and methods of forming them. [Background technology]

[0002] Solid-state lithium batteries are expected to offer higher energy density and faster recharge times, with fewer safety concerns, compared to conventional lithium-ion batteries. Current solid electrolyte materials include oxides, halides, sulfides, fluorides, and solid polymer electrolytes. The stability of the electrolyte material can affect the performance of solid-state lithium batteries. The industry continues to need improved solid electrolyte and electrode materials. [Brief explanation of the drawings]

[0003] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. [Figure 1A] 1 includes an illustrative diagram of a cathode material according to an embodiment. [Figure 1B] 1 includes an illustrative diagram of a cathode material according to an embodiment. [Figure 2] 1 includes an illustrative diagram including a cross-sectional view of a cathode material according to one embodiment. [Figure 3] 1 includes a cross-sectional illustrative view of a multi-layer structure according to one embodiment. [Figure 4] 1 includes an illustrative diagram of a process according to one embodiment. [Figure 5A] Included are plots of differential capacitance versus voltage for the samples. [Figure 5B] 1 includes an illustrative diagram of the crystalline structure of the cathode material. [Figure 5C] 1 includes a plot of differential capacitance versus voltage for a sample according to one embodiment. [Figure 5D] Included is a plot of the specific capacity of the sample versus cycle number. [Figure 6A] Included is a plot of the specific capacity of the sample versus cycle number. [Figure 6B]1 includes plots of −Zlmag vs. Zre for samples according to embodiments. [Figure 6C] 10 includes plots of Zre versus ω-1 / 2 for samples according to an embodiment. [Figure 7] Included is a plot of the specific capacity of the sample versus cycle number. [Figure 8] Included are plots of the specific capacitance versus voltage of the samples.

[0004] Those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention. The use of the same reference numbers in different figures indicates similar or identical items. DETAILED DESCRIPTION OF THE INVENTION

[0005] The following description in combination with the figures is provided to aid in understanding the teachings disclosed herein. The following discussion focuses on particular implementations and embodiments of the teachings. This focus is provided to help explain the teachings and should not be construed as a limitation on the scope or applicability of the teachings.

[0006] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of features is not necessarily limited to only those features and may include other features not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" refers to an inclusive "or" and not an exclusive "or." For example, condition A or B can be satisfied by any one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0007] The use of "a" or "an" is used to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description includes one or at least one, and the singular should be read as including the plural and vice versa, unless it is clear that something else is meant.

[0008] 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 invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting.

[0009] Embodiments herein relate to a cathode material comprising a substrate and a coating material covering at least a portion of the substrate, wherein the substrate can comprise a cathode active material. In one embodiment, the substrate can comprise particles comprising the cathode active material. The cathode material can be a suitable component of a non-aqueous battery, such as a solid-state battery, including a solid-state lithium battery, a solid-state sodium battery, or any combination thereof. In exemplary embodiments, the cathode material can be in direct contact with a solid electrolyte material, such as a solid halide-based electrolyte material or another solid electrolyte material. The cathode material can have improved ion diffusion rates, capacity retention, reversible phase transition, or any combination thereof. The cathode material can also facilitate improved stability of the solid electrolyte material and improved performance of the solid-state battery.

[0010] Further embodiments relate to methods of forming cathode materials, which allow for improved formation of cathode materials and can facilitate the formation of cathode materials with improved properties.

[0011] In one embodiment, the cathode material is a fluorocarbon (referred to in this disclosure as "CF x ") and M2CO3, where M comprises an alkali metal. In one embodiment, M can comprise Li, Na, Cs, Rb, or a combination thereof. In one example, M can comprise Li. In another example, M can comprise Na. In a further example, M can comprise Li and another alkali metal, such as Na, Cs, or both. In a particular example, M can consist essentially of at least one of Li and Na.

[0012] In one embodiment, the coating material can include MF. In one aspect, MF can include LiF, NaF, CsF, RbF, or a combination thereof. In one example, MF can include LiF. In another example, MF can include NaF. In a further example, MF can include LiF and another alkali metal fluoride, such as NaF, CsF, or both. In a particular example, MF can consist essentially of at least one of LiF and NaF.

[0013] In one embodiment, the coating can include fluorocarbons, including stoichiometric carbon monofluoride, substoichiometric carbon monofluoride, or any combination thereof. In one aspect, the fluorocarbons can include CF1, C2F4, CF2, CF3, CF4, or any combination thereof. In a specific aspect, the coating can include CF4, CF2, or both. In another aspect, the coating can include a specific ratio between fluorocarbon species. XPS can be used to detect the fluorocarbon species. In another specific aspect, the coating can include CF1.

[0014] In one embodiment, the cathode material can include a coating of a particular average thickness, which can promote improved performance and / or properties of the cathode material. In one aspect, the coating can have an average thickness of less than 1 micron. For example, the coating can have an average thickness of at most 100 nm, e.g., at most 80 nm, at most 70 nm, at most 60 nm, at most 50 nm, at most 40 nm, at most 30 nm, or at most 20 nm. In another example, the coating can have an average thickness of at least 1 nm, e.g., at least 2 nm, at least 5 nm, at least 7 nm, at least 10 nm, at least 13 nm, at least 15 nm, at least 18 nm, or at least 20 nm. Furthermore, the coating can have an average thickness within a range that includes any of the minimum and maximum values ​​described herein.

[0015] As used herein, the average thickness of the coating may be determined by utilizing transmission electron microscopy to analyze a cathode material sample having a sample size that is statistically significant to represent the cathode material.

[0016] In one embodiment, the coating can cover at least a portion of the substrate. In one aspect, the coating can extend continuously along at least a portion of the substrate. In another aspect, the coating can have a specific coverage on the substrate, which can facilitate improved performance and / or properties of the cathode material. For example, the coating can cover at least 20%, at least 30%, at least 40%, at least 50%, or a majority of the substrate. In a further example, the coating can cover essentially the entire substrate. In other examples, the coating can cover 99% or less, 96% or less, 90% or less, 88% or less, 85% or less, or 80% or less of the substrate. Furthermore, in certain examples, the coating can have a coverage that is a range that includes any of the minimum and maximum percentages described herein.

[0017] In one embodiment, the cathode material can be in the form of a powder. In another embodiment, the cathode material can be in the form of a suspension. In yet another embodiment, the cathode material can include a substrate in the form of particles. In one aspect, the substrate can include a plurality of particles comprising a cathode active material. In another aspect, at least a portion of the particles can have a coating. For example, at least 20 wt%, at least 30 wt%, at least 40 wt%, or at least 50 wt%, based on the total weight of the particles, can include a coating. In certain aspects, at least a majority, e.g., greater than 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, or at least 95 wt%, based on the total weight of the particles, can include a coating. In certain examples, essentially all of the particles, e.g., at least 95 wt% or at least 98 wt% of the particles based on the total weight of the particles, can include a coating. More specifically, all of the particles, e.g., 100 wt% of the particles, can include a coating. In further aspects, not all of the particles can include a coating. For example, 99% or less by weight of the particles can comprise a coating, e.g., 98% or less by weight, 96% or less by weight, 94% or less by weight, 92% or less by weight, 90% or less by weight, or 88% or less by weight of the particles can comprise a coating, based on the total weight of the particles. Further, the cathode material can include particles with a content that can range between and include any of the minimum and maximum percentages described herein.

[0018] In further embodiments, the cathode material may include particles in which at least 20% of the total number of particles include a coating, e.g., at least 30%, at least 40%, or at least 50% of the total number of particles include a coating. In certain embodiments, at least a majority of the total number of particles, e.g., greater than 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95%, may include a coating. In certain examples, essentially all of the particles, e.g., at least 95% or at least 98% of the particles of the total number of particles, may include a coating. More specifically, all of the particles may include a coating. In other embodiments, not all of the particles may include a coating. For example, 99% or less of the particles may include a coating, e.g., 98% or less, 96% or less, 94% or less, 92% or less, 90% or less, or 88% or less of the particles of the total weight of the particles may include a coating. Furthermore, the cathode material may include particles with a content of coating, which may be within a range including any of the minimum and maximum percentages described herein. As disclosed herein, a total of at least 200 randomly selected different particles are analyzed to determine the percentage of the number of particles that have a coating.

[0019] In one embodiment, the content of particles containing a coating can be determined by using energy dispersive X-ray analysis (EDX). A cathode material sample having a sample size that statistically represents the cathode material can be analyzed by EDX. The number or weight of particles containing a coating can be determined based on the EDX results, and the percentage of particles containing a coating relative to the total number or weight of particles analyzed can be used as the content of particles containing a coating for a batch of cathode material.

[0020] Referring to FIG. 1A , an exemplary cathode material 100 is illustrated. The cathode material 100 may include a plurality of particles including a substrate in the form of particles 108 and a coating 106 covering the particles 108. The coating 106 may be in direct contact with the particles 108. In the illustrated example, the cathode material may include particles 102 including a coating 106 that may essentially completely cover the particles 108. The particles 102 may have a substantially uniform coating thickness. In another embodiment, the cathode material may include particles having variations in coating thickness. For example, the coating thickness may decrease and / or increase along the surface of the coated particle.

[0021] In one particular example, cathode material 100 can include coated particles 103, and coating 106 can essentially completely cover particles 108 or can have variations in coating thickness.

[0022] In certain examples, cathode material 100 can include coated particles 104, where a portion of the particle can be covered by a coating 106. In the embodiment illustrated in FIG. 1A, the particle 104 can have a variation in coating thickness along the surface of the particle 108. In other embodiments, the partially coated particles and / or the fully coated particles can have a substantially uniform coating thickness.

[0023] In another embodiment, the cathode material may include coated particles, and at least some of the particles may include a substantially uniform coating thickness along the coated surface. For example, at least 20% of the total number of coated particles may include a substantially uniform coating thickness, e.g., at least 30%, at least 40%, or at least 50% of the particles may include a substantially uniform coating thickness. In certain examples, a majority of the coated particles may include a coating having a substantially uniform thickness, e.g., at least 55%, at least 60%, at least 70%, at least 80%, or at least 90% of the coated particles may include a coating having a substantially uniform thickness. In certain examples, essentially all of the coated particles may include a coating having a substantially uniform thickness. In further examples, 98% or less, 95% or less, 92% or less, 90% or less, or 88% or less of the coated particles may include a substantially uniform coating thickness.

[0024] In a further example, the cathode material 100 can include uncoated particles 109. As illustrated, the cathode material 100 can include a majority of particles that include a coating 106.

[0025] In another embodiment, the cathode material 100 can include up to 50 wt% uncoated particles, based on the total weight of the particles, such as less than 50 wt%, 40 wt% or less, 30 wt% or less, 20 wt% or less, 10 wt% or less, 5 wt% or less, 3 wt% or less, or 1 wt% or less uncoated particles, based on the total weight of the particles. The content of uncoated particles can be determined using EDX in a manner similar to the embodiment described for determining the content of particles that include a coating.

[0026] In yet another embodiment, the cathode material 100 can include up to 50% uncoated particles relative to the total number of particles, such as less than 50%, 40% or less, 30% or less, 20% or less, 10% or less, 5% or less, 3% or less, or 1% or less of the total number of particles. In certain embodiments, the cathode material can be essentially free of uncoated particles.

[0027] In one embodiment, the cathode material can include particles having an average particle size. In one example, the average particle size can be submicron to hundreds of microns, or even larger. In another example, the average particle size can be 1 micron to 500 microns. In yet another example, the average particle size can be 1 micron to 10 microns, e.g., 2 microns to 5 microns. In yet another example, the cathode material can include loose particles, aggregated particles, agglomerates, or any combination thereof. One skilled in the art will understand that the cathode material can include any average particle size that can be suitable for the application of the cathode material.

[0028] In one embodiment, the cathode material may be in the form of a sheet, tape, block, film, or another shape, or any combination. Referring to FIG. 1B , a cross-sectional view of an exemplary cathode material 110 is illustrated, according to one embodiment. The cathode material 110 may include a body 111 containing a plurality of particles 112. The body 110 may include a length L and a thickness t. In one embodiment, the particles 112 may include any or all of the features described with respect to the particles 102, 103, 109, and 104 illustrated in FIG. 1A . It should be understood that the cathode material 110 may include any or all of the features described with respect to the cathode material 100, except that the cathode materials 110 and 100 may be in different forms.

[0029] In one embodiment, the cathode material may include a plurality of particles, at least some of which may have a coating coverage of at least 50% relative to their surface area. For example, at least 30%, e.g., at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% of the particles relative to the total number of particles may have a coating coverage of at least 50% relative to their surface area. In another example, all or essentially all of the particles may have a coating coverage of at least 50% relative to their surface area. In a further example, up to 95% of the particles relative to the total number of particles, e.g., up to 90%, up to 80%, or up to 70% of the particles, may have a coating coverage of at least 50% relative to their surface area. Furthermore, the cathode material may include particles having a coating coverage of at least 50%, the content of which may be within a range including any of the minimum and maximum percentages described herein.

[0030] In further embodiments, the cathode material 100 can include a specific average coating coverage, which can facilitate improved properties and / or performance of the cathode material. The average coating coverage can be determined based on an analysis of a cathode material sample having a sample size that is statistically representative of the cathode material. Transmission electron microscopy can be used to determine the coating coverage of each particle relative to the particle's surface area. The average coating coverage can be the sum of the coating coverages of all analyzed particles divided by the number of particles. In one aspect, the cathode material can include an average coating coverage of at least 30%, e.g., at least 40%, at least 50%, at least 60%, at least 70%, at least 75%, at least 80%, at least 90%, or at least 95%. In certain examples, the cathode material can include an average coating coverage of 100%. In other aspects, the cathode material can include an average coating coverage of 99% or less, 96% or less, 93% or less, 90% or less, 88% or less, 85% or less, or 80% or less. Additionally, the cathode material can include an average coating coverage range that includes any of the minimum and maximum percentages described herein.

[0031] In one embodiment, the cathode material may include a substrate in the form of a tape, sheet, block, film, etc., or any combination thereof. The substrate may include a cathode active material. Referring to Figure 2, a cross-sectional view of an exemplary cathode material 120 is illustrated, including a substrate 126 including a cathode active material and a coating 124 overlying the substrate 126. The substrate may include a length L and a thickness t.

[0032] Substrate 126 can include a major surface 127 and another major surface 128 opposite major surface 127. Coating 124 can cover at least one of major surfaces 127 or 128, such as major surface 127 as illustrated. One skilled in the art can understand that coating 124 can cover major surface 128. In at least one embodiment, cathode material 120 can include coating 124 covering both major surfaces 127 and 128 of substrate 126.

[0033] In another embodiment, the cathode material 120 can include a coating 124 that can cover at least a portion of the substrate 126. In further embodiments, the coating 124 can cover at least a portion of the major surfaces 127 and / or 128 of the substrate 126. In further embodiments, the coating 124 can have a specific coverage on the substrate 126, which can facilitate improved performance and / or properties of the cathode material. For example, the coating 124 can cover at least 20% of the major surface of the substrate, such as at least 30%, at least 40%, at least 50%, or a majority of the major surface of the substrate. In further examples, the coating can cover essentially the entire major surface of the substrate. In other examples, the coating can cover 99% or less, 96% or less, 90% or less, 88% or less, 85% or less, or 80% or less of the major surface of the substrate. Furthermore, in certain examples, the coating 124 can have a coating coverage that is a range that includes any of the minimum and maximum percentages described herein.

[0034] In one embodiment, the substrate can include a coating in the form of a thin film. In a further embodiment, the cathode material can include a coating that can be relatively dense. In one aspect, the coating can have a density of at least 90% of the theoretical density, e.g., at least 93%, at least 95%, at least 98%, or even at least 99% of the theoretical density. In particular, the coating can have a density higher than that when the coating is formed by a densification process that includes calcination. In another aspect, the coating can have relatively low porosity. The porosity can be constituted by voids that may be present in the coating. For example, the coating can include a minimal amount of pores within the coating. The porosity can differ from the uncoated areas of the particle surface. For example, the cathode material can include particles that can be partially covered by the coating, and the coating can include a minimal amount of pores. In certain aspects, the cathode material can include a coating that includes 7 vol% or less of porosity, e.g., 5 vol% or less, 3 vol% or less, or 1 vol% or less, based on the total volume of the coating. In certain examples, the coating may be essentially free of pores. In other examples, the cathode material may include a coating that includes at least 0.1 vol.%, e.g., at least 0.4 vol.%, at least 0.7 vol.%, at least 1 vol.%, or at least 2 vol.%, of porosity relative to the total volume of the coating. Further, the cathode material may include a coating having a porosity within a range including any of the minimum and maximum percentages described herein.

[0035] In one embodiment, the cathode material can include a coating that can have a relatively smooth surface. In one aspect, the coating can have a relatively low surface roughness. For example, the surface roughness of the coating can be lower than the surface roughness of a coating formed by a densification process that includes firing. The surface roughness can be determined by analyzing a cathode material sample using scanning electron microscopy, transmission electron microscopy, or both, having a sample size that is statistically representative of the cathode material.

[0036] In one embodiment, the cathode material can include a coating having a substantially uniform thickness. In another embodiment, the coating can include thickness variations along the coated area of ​​the substrate. In certain embodiments, the coating can have a specific average thickness variation along the coated surface, which can facilitate improved properties and / or performance of the cathode material. In one example, the average thickness variation can be within ±50% of the average coating thickness, e.g., within ±40%, ±30%, ±20%, ±10%, or ±5% of the average coating thickness.

[0037] In one embodiment, the cathode material may contain a specific content of M2CO3,CF3, which may facilitate improved properties and / or performance of the cathode material. x In another embodiment, the coating may include a coating containing specific relative contents of M2CO3, CF3, and / or MF, which may facilitate improved properties and / or performance of the cathode material. x , and / or MF. The relative content can be determined by X-ray photoelectron spectroscopy (XPS) analysis. Those skilled in the art will understand that the relative content is relative to the content of a certain element. In this disclosure, M2CO3, CF x The relative content of MF compared to the content of Ni as determined by XPS as follows: A full survey spectrum containing all elements present on the surface of the coated cathode active material can be acquired. The peak area associated with each peak in the survey spectrum is then extracted. The extracted peak areas are corrected by considering the sensitivity factor of each element (i.e., dividing the peak intensity by the element's sensitivity factor), and all peak areas are normalized to Ni.

[0038] In certain embodiments, the relative content of M2CO3 can be at least 0.4, at least 0.6, at least 0.7, at least 0.8, at least 0.9, or at least 1.0. Additionally or alternatively, the relative content of M2CO3 can be 1.5 or less, 1.3 or less, 1.1 or less, 0.9 or less, or 0.8 or less. Further, the relative content of M2CO3 can be a range that includes any of the minimum and maximum values ​​described herein.

[0039] In one embodiment, the coating has a CF of at least 0.05, e.g., at least 0.07, at least 0.09, at least 0.11, or at least 0.13. x Additionally or alternatively, the relative content of CF x The relative content of CF may be 0.42 or less, 0.40 or less, 0.38 or less, 0.35 or less, 0.32 or less, 0.30 or less, 0.28 or less, 0.27 or less, 0.25 or less, 0.23 or less, 0.21 or less, 0.18 or less, 0.15 or less, or 0.13 or less. x The relative content of may be a range including any of the minimum and maximum values ​​described herein.

[0040] In one embodiment, the coating can include a relative MF content of at least 1.2, at least 1.4, at least 1.7, at least 1.9, at least 2.1, at least 2.3, at least 2.5, at least 2.7, at least 2.9, at least 3.0, or at least 3.2. Additionally or alternatively, the relative MF content can be 6.4 or less, 6.1 or less, 5.8 or less, 5.5 or less, 5.2 or less, 4.9 or less, 4.6 or less, 4.2 or less, 3.9 or less, 3.7 or less, 3.5 or less, 3.1 or less, or 3.0 or less. Further, the relative MF content can be a range including any of the minimum and maximum values ​​described herein.

[0041] In one embodiment, the coating may facilitate improving the properties and / or performance of the cathode material. xThe composition may include a specific content ratio C1 of the relative content of M2CO3 to the relative content of M2CO3. In further embodiments, the ratio C1 can be at least 3.6, at least 3.8, at least 4.1, at least 4.5, at least 4.8, at least 5.1, at least 5.3, at least 5.7, at least 5.9, at least 6.3, at least 6.7, at least 6.9, at least 7.2, at least 7.5, at least 7.8, at least 8.1, at least 8.3, at least 8.5, or at least 8.7. Additionally or alternatively, the ratio C1 can be 11.5 or less, 11.2 or less, 10.8 or less, 10.5 or less, 10.1 or less, 9.7 or less, 9.4 or less, 9.1 or less, 8.8 or less, 8.6 or less, or 8.3 or less. Furthermore, the ratio C1 can be a range including any of the minimum and maximum values ​​described herein.

[0042] In one embodiment, the coating can include a particular content ratio C2 of the relative content of MF to the relative content of M2CO3, which can facilitate improved properties and / or performance of the cathode material. In further embodiments, the ratio C2 can be at least 1.2, at least 1.4, at least 1.6, at least 1.8, at least 2.1, at least 2.3, at least 2.5, at least 2.7, at least 2.9, at least 3.0, or at least 3.2. Additionally or alternatively, the ratio C2 can be 6.4 or less, 6.1 or less, 5.8 or less, 5.5 or less, 5.2 or less, 4.9 or less, 4.6 or less, 4.3 or less, 4.1 or less, 3.8 or less, 3.5 or less, 3.2 or less, 3.1 or less, or 2.9 or less. Furthermore, the ratio C2 can be a range including any of the minimum and maximum values ​​described herein.

[0043] In one embodiment, the coating may facilitate improving the properties and / or performance of the cathode material. xThe present invention may include a specific content ratio C3 of the relative content of MF to the relative content of MF. In further embodiments, the ratio C3 may be 35.4 or less, 34.1 or less, 32.8 or less, 31.5 or less, 30.2 or less, 28.9 or less, 28.6 or less, 27.3 or less, 26.1 or less, 25.8 or less, or 24.5 or less. Additionally or alternatively, the ratio C3 may be at least 6.3, at least 7.8, at least 9.2, at least 10.5, at least 11.1, at least 12.3, at least 14.5, at least 15.2, at least 16.9, at least 18.0, at least 19.5, at least 21.5, at least 23.8, at least 24.5, at least 25.8, or at least 26.2. Furthermore, the ratio C3 may be a range including any of the minimum and maximum values ​​described herein.

[0044] In one embodiment, the cathode material may include a specific concentration of fluoride that may help improve the properties and / or performance of the cathode material. In a further embodiment, the coating may include an organic fluoride, such as a fluorocarbon, and an inorganic fluoride, such as MF. In another embodiment, the cathode material may include a specific total concentration (C TF ) of organic and inorganic fluorides. For example, the total concentration (C TF ) may be greater than 0, e.g., at least 5 μg / g, at least 20 μg / g, at least 50 μg / g, at least 90 μg / g, at least 110 μg / g, at least 150 μg / g, at least 205 μg / g, at least 235 μg / g, or greater than 235 μg / g. In certain examples, the total concentration (C TF ) can be at least 236 μg / g, at least 240 μg / g, at least 260 μg / g, at least 290 μg / g, at least 310 μg / g, at least 335 μg / g, at least 355 μg / g, at least 370 μg / g, or at least 390 μg / g. TF) can be less than 805 μg / g, e.g., at most 800 μg / g, at most 785 μg / g, at most 770 μg / g, at most 730 μg / g, at most 695 μg / g, at most 650 μg / g, at most 601 μg / g, at most 570 μg / g, at most 515 μg / g, at most 475 μg / g, at most 435 μg / g, or at most 395 μg / g. Additionally, the total concentration can be a range that includes any of the minimum and maximum values ​​described herein.

[0045] In another embodiment, the cathode material contains a specific concentration of organic fluoride (C ) that may help improve the properties and / or performance of the cathode material. OF For example, the concentration of organic fluorides (C OF ) can be at least 0.5 μg / g, e.g., at least 1 μg / g, at least 2 μg / g, at least 4 μg / g, at least 6 μg / g, at least 8 μg / g, at least 10 μg / g, at least 12 μg / g, or at least 14.5 μg / g. OF ) can be less than 32.7 μg / g, e.g., at most 32 μg / g, at most 30 μg / g, at most 27 μg / g, at most 25 μg / g, at most 21 μg / g, at most 19 μg / g, at most 17 μg / g, at most 16 μg / g, at most 15 μg / g, or at most 14.5 μg / g. OF ) may be a range that includes any of the minimum and maximum values ​​stated herein.

[0046] In another embodiment, the cathode material contains a specific concentration of inorganic fluoride (C ) that may help improve the properties and / or performance of the cathode material. IF For example, the concentration of inorganic fluoride (C IF ) may be greater than 0, e.g., at least 25 μg / g, at least 40 μg / g, at least 75 μg / g, at least 90 μg / g, at least 125 μg / g, or at least 156.5 μg / g, or at least 202.3 μg / g. In certain examples, the concentration of inorganic fluoride (C IF) may be greater than 202.3 μg / g, e.g., at least 205 μg / g, at least 210 μg / g, at least 240 μg / g, at least 280 μg / g, at least 310 μg / g, at least 335 μg / g, at least 355 μg / g, at least 370 μg / g, or at least 377.5 μg / g. IF ) can be less than 770.8 μg / g, e.g., at most 769 μg / g, at most 750 μg / g, at most 740 μg / g, at most 725 μg / g, at most 680 μg / g, at most 640 μg / g, at most 615 μg / g, at most 605 μg / g, at most 581 μg / g, at most 540 μg / g, at most 515 μg / g, at most 475 μg / g, at most 435 μg / g, at most 395 μg / g, at most 385 μg / g, or at most 378 μg / g. IF ) may be a range that includes any of the minimum and maximum values ​​stated herein.

[0047] In a further embodiment, the cathode material has a concentration of organic fluoride (C OF ) versus inorganic fluoride concentration (C IF ) at a specific concentration ratio (C I / O In one example, the concentration ratio (C I / O ) may be greater than 22.5, e.g., at least 23, at least 24, at least 25, or at least 26. In another example, the concentration ratio (C I / O ) can be at most 81, at most 75, at most 70, at most 65, at most 61, at most 56, at most 52, at most 48, at most 43, at most 39, at most 34, at most 31, at most 28, or at most 26. Furthermore, the concentration ratio (C I / O ) may be a range that includes any of the minimum and maximum values ​​stated herein.

[0048] In one embodiment, the substrate may include an active cathode material containing an oxide. Exemplary oxides may include one or more metal elements among alkali metals, 3d metals, 4d metals, 5d metals, rare earth metals, and alkaline earth metals. In a further example, the oxide may include an alkali transition metal oxide. In a specific example, the alkali metal may include Li, Na, or a combination thereof. In another specific example, the oxide may include at least one 3d metal such as Ni. In a specific embodiment, the cathode active material may include a lithium-doped nickel oxide material. In one example, the lithium-doped nickel oxide material may include an additional dopant. In a more specific embodiment, the cathode active material may include a Li-Ni-Mn-Co oxide. A specific example may include LiNi x Mn y Co z O2, where x > 0, y ≥ 0, z ≥ 0, x + y + z = 1, and y + z > 0. In a more specific example, 0.3 < X < 0.8, 0.2 < Y < 0.3, 0.1 < Z < 0.4. As an even more specific example, LiNi 0.6 Mn 0.2 Co 0.2 O2 may be included.

[0049] Referring to FIG. 3, a multilayer structure 300 of one embodiment is illustrated, including a layer 304 covering the electrolyte layer 306 and a third layer 302 on the opposite side of the layer 304 across the electrolyte layer 306. The layer 304 may include a cathode material described in the embodiments herein. For example, the layer 304 may include the cathode material 100 illustrated in FIG. 1A or the cathode material 110 illustrated in FIG. 1B. In another example, the layer 304 may include the cathode material 120 illustrated in FIG. 2. The electrolyte layer 306 may include a solid electrolyte material.

[0050] The layer 304 may include a thickness t extending in the stacking direction or y-axis of the multilayer structure 300, a length L extending in the x-axis, and a width extending in the z-axis. It can be understood that the thickness, width, and length of other components such as the layers 306 and 302 may extend in the same direction up to the layer 304, respectively.

[0051] In one embodiment, layer 304 can be a cathode layer. In one aspect, cathode layer 304 can include a cathode material and, optionally, an additive. Exemplary additives can include a binder material, such as an organic binder, a pore former, a filler, such as a conductive filler (e.g., conductive carbon), or any combination thereof. In another embodiment, layer 304 can be a composite layer including a cathode material and an ion-conducting material. For example, layer 304 can include a solid electrolyte material described in embodiments herein. In further embodiments, layer 304 can include multiple layers. In certain embodiments, a coating of cathode material can be in direct contact with electrolyte layer 306.

[0052] In one embodiment, the electrolyte layer may include a solid electrolyte material including a halide-based electrolyte material, a sulfide-based electrolyte material, an oxide-based electrolyte material, a hydroxyhalide, an oxyhalide, an organic electrolyte material, such as a polymer electrolyte, or any combination thereof.

[0053] In certain embodiments, the cathode materials may be particularly suitable for use with solid electrolyte materials that may be prone to degradation, such as sulfide electrolyte materials, halide electrolyte materials, or the like, or any combination thereof.

[0054] In certain embodiments, the electrolyte layer may include a halide-based electrolyte material. In one aspect, the halide-based electrolyte material may include anions containing a halogen from the group consisting of F, Cl, Br, and I. In certain aspects, the halide-based electrolyte material may include at least two halogen anions. More specific examples of halide-based electrolyte materials may include at least two halogen anions selected from the group consisting of F, Cl, and Br.

[0055] In a further embodiment, the halide-based electrolyte material is M 3-z (Me k+ ) f X 3-z+k*fwhere -3≦z<3, 2≦k≦6, and 0≦f≦1, M may include an alkali metal element, and X may include a halogen. Me may include a divalent metal element, a trivalent metal element, a tetravalent metal element, a pentavalent metal element, a hexavalent metal element, or any combination thereof.

[0056] In certain embodiments, the halide-based electrolyte material is Li 3-x-f M f RE 1-y Me k y (Cl 1-u-p-q Br u F p I q ) 6-x+y*(k-3) where -1<=x<=1, 0<=y<=1, 0<=u<1, 0<=p<=1 / 3, 0<=q<=1 / 6, 0<(u+p+q)<1, and 0<=f<=0.3. In certain embodiments, the halide electrolyte material is Li 3-x RE 1-y Me k y (Cl 1-u Br u ) 6-x+y*(k-3) where 0.08<=u<=0.67. M is at least one alkali metal element other than Li, and RE can be a rare earth element. Me is at least one element selected from the group consisting of Group IIIB elements, Group IVB elements, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Al, Sn, Pb, Bi, Sb, Mg, Ca, Ga, and Ge, where Me is different from RE, and k can be the valence of Me.

[0057] In a further embodiment, the halide electrolyte material is Li a M a Me b Me' b’ X c X' c’ and may have a specific crystallographic phase transition, where X and X' may represent different halogens and Me' may represent another Me. In one aspect, the crystallographic phase transition is represented by (b / (b+b')) t* 0.84 t * 1.16, (b / (b+b')) t may correspond to a crystallographic phase transition in the crystallographic phase diagram at a temperature between 20° C. and 25° C. In a further embodiment, the crystallographic phase transition is (c / (c+c')) t * 0.84 <c / (c+c’)<(c / (c+c’)) t * 1.16, (c / (c+c')) t can correspond to a crystallographic phase transition in a crystallographic phase diagram at a temperature between 20° C. and 25° C. In yet another embodiment, the crystallographic phase transition is (a / (a+a')) t * 0.84 t * 1.16, (a / (a+a')) t may correspond to a crystallographic phase transition in the crystallographic phase diagram at a temperature between 20° C. and 25° C. In a further embodiment, the halide electrolyte material may include NH4X, where X may be a halogen selected from Cl, Br, F, or I, and NH4 + may be partially substituted with an alkali metal.

[0058] Specific examples of solid electrolyte materials include Li 3-a Na a Y(Br x Cl y )6, where 0≦a≦0.33 and x+y=1. In more specific examples, x≦y. Even more specific examples of solid electrolyte materials include Li3YBr6, Li3YCl6, Li3Y(Cl 0.67 Br 0.33 )6, Li3Y(Cl 0.79 Br 0.21 )6, Li3Y(Br 0.35 Cl 0.65 )6, Li3Y(Cl 0.8 Br 0.2 )6, Li3Y(Cl 0.19 Br 0.81 )6, Li3(Y 0.95 Yb​​0.05 )1(Cl 0.83 Br 0.17 )6, Li3(Y 0.95 In 0.05 )(Cl 0.9 Br 0.1 )6, Li 2.95 (Y 0.95 Zr 0.05 )(Cl 0.9 Br 0.1 )6, Li3(Y 0.85 In 0.15 )Cl6, (Li 0.955 Na 0.045 )3Y1Cl6, Li3Y(Cl 0.41 Br 0.59 )6, Li3Y(Cl 0.62 Br 0.38 )6, Li3Y(Cl 0.67 Br 0.33 )6, Li3Y(Cl 0.79 Br 0.21 ) 6, or any combination thereof.

[0059] In further embodiments, the halide material may include a relatively low content of impurity phases, including water-insoluble impurity phases, binary halide phases, ternary halide phases, or any combination thereof. For example, the halide material may include one or more water-insoluble impurity phases at a total content of less than 0.11 wt.%, based on the total weight of the halide material, such as 0.1 wt.% or less, 0.09 wt.% or less, 0.08 wt.% or less, 0.07 wt.% or less, 0.05 wt.% or less, 0.04 wt.% or less, 0.03 wt.% or less, 0.01 wt.% or less, 0.008 wt.% or less, 0.006 wt.% or less, 0.004 wt.% or less, or 0.003 wt.% or less, based on the total weight of the halide material. In some cases, the majority of the water-insoluble impurity phase may include one or more phases of rare earth oxyhalides, Me oxyhalides, rare earth oxides, Me oxides, or any combination thereof. In another example, the water-insoluble impurity phase can consist essentially of one or more phases of rare earth oxyhalides, oxyhalides of Me, rare earth oxides, oxides of Me, or any combination thereof.

[0060] In a further example, the halide material may include a binary halide phase with a total content of 10 wt% or less, e.g., 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, or 0.5 wt% or less, based on the total weight of the halide material. The binary halide may include a cation of a metal element selected from the group consisting of Li, M, Me, and RE.

[0061] In a further example, the halide material may contain 6 wt. % or less of ternary halide phases, based on the total weight of the halide material, e.g., a total content of ternary halide phases of 5 wt. % or less, 3 wt. % or less, 2 wt. % or less, 1 wt. % or less, or 0.5 wt. % or less, based on the total weight of the halide material. Exemplary ternary halides may contain two metal cations and one halide anion, such as alkali metal-rare earth metal halides, or one metal element and two halide anions, or both. Exemplary metal cations may include cations of Li, M, RE, and / or Me metal elements. In certain embodiments, the halide material may be essentially free of binary halide phases, ternary halide phases, oxynitride phases, and oxyhalide phases. In more specific embodiments, the halide material may consist essentially of a single phase.

[0062] In further embodiments, the solid electrolyte material may include a single crystal or a polycrystalline material. In another embodiment, the solid electrolyte material may include an oriented polycrystalline halide electrolyte material, where the grains of the polycrystalline halide electrolyte material may be oriented in a particular crystallographic direction that may promote improved ionic conductivity. For example, the grains may be oriented such that the ionic conductivity in the direction of the thickness t of the electrolyte layer 306 may be greater than the ionic conductivity in the direction of the length L or width of the electrolyte layer or in another crystallographic direction.

[0063] In one embodiment, the coating of the cathode material may be in direct contact with the solid electrolyte material. For example, the coatings 106 and 124 illustrated in Figures 1A and 2, respectively, may be in direct contact with the electrolyte layer 306 in Figure 3.

[0064] Referring to FIG. 3 , an interface 305 between layers 304 and 306 is illustrated. In one embodiment, at least a portion of interface 305 can be defined by a coating of cathode material and solid electrolyte material. In certain embodiments, multilayer structure 300 can include interface 305 including a specific contact area defined by the coating of cathode material and solid electrolyte material, which can facilitate improved performance and / or properties of the multilayer structure. In one aspect, the contact area can be at least 50% of the entire interface 305, e.g., at least 55%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% of the entire interface. In certain embodiments, the entire interface 305 can be defined by the coating and solid electrolyte material. In further aspects, the contact area can be up to 99% of the entire interface 305, e.g., up to 95%, at most 93%, at most 90%, at most 87%, or at most 85% of the entire interface 305. Additionally, the contact area defined by the coating and the solid electrolyte material can be within a range including any of the minimum and maximum percentages described herein.

[0065] In one embodiment, the third layer 302 can be an anolyte, an anode, another electrolyte layer, or another component of a solid-state battery, or any combination thereof. Those skilled in the art will understand that the multilayer structures contemplated in this disclosure do not necessarily include three layers, and in some cases, the multilayer structure 200 can include a cathode layer 304 covering an electrolyte layer 306 without a third layer 302 as illustrated.

[0066] The cathode materials described in embodiments herein have improved properties compared to cathode materials having the same cathode active material without a coating. For example, the cathode materials may have improved stability, reduced reactivity with solid electrolyte materials, improved reversible phase transition, wettability, processability, Li-ion diffusion, or any combination thereof. In certain embodiments, the cathode materials may be suitable components of Li and / or Na solid-state batteries and may promote improved performance of the solid-state battery. In more specific embodiments, the cathode materials may be in direct contact with halide solid-state electrolyte materials, which may significantly improve the stability of the solid-state electrolyte material and the overall performance of the solid-state battery. Such improvements may be reflected by improved charge and recharge capacity, specific capacity over charge-recharge cycles, reduced degradation of the electrolyte material, or any combination thereof.

[0067] In one embodiment, a cathode material, such as cathode materials 100, 110, and 120 illustrated in Figures 1A, 1B, or 2, respectively, can include a particular σ- (Warburg coefficient) that can facilitate improved properties and performance of the cathode material. In one aspect, the cathode material has a resistance of 2940 Ωs -1 For example, 2800Ωs -1 Below, 2500Ωs -1 Below, 2200Ωs -1 Below, 2000Ωs -1 Below, 1800Ωs -1 Below, 1600Ωs -1 Below, 1490Ωs -1 or less, or 1350Ωs -1 In one embodiment, the cathode material may have a σ-(Warburg coefficient) of at least 500 Ωs -1 , at least 700Ωs -1 , at least 850Ωs -1 , at least 1000Ωs -1 , at least 1150Ωs -1 , at least 1300Ωs -1 , or at least 1400Ωs -1Additionally, the cathode material may have a σ-(Warburg coefficient) in a range that includes any of the minimum and maximum values ​​described herein.

[0068] σ- (Warburg coefficient) can be calculated as follows:

[0069] A cell battery can be used for testing. The cell battery contains a cathode material and Li3Y(Cl 0.8 Br 0.2 ) 60 wt. % of the cathode material and 40 wt. % of LiYCl 0.8 Br 0.2 )6 and 0.5 wt% conductive carbon, a pressed cathode pellet, Li foil as the anode, and LiY(Cl 0.8 Br 0.2 ) 6 pressed pellets of electrolyte.

[0070] The cathode Li diffusion is calculated using the slope of the sloping line at low frequencies, such as 0.1 Hz to 1 Hz, in the electrochemical impedance spectroscopy spectrum and the following equation: Z' re =R e +R c +σ w ω -1 / 2

[0071] Dion=R 2 T 2 / 2n 4 F 4 A 2 C 2 ion σ 2 (In the formula, Z' re represents the Warburg impedance (impedance at low frequencies), and R e represents the electrolyte resistance, and R ct represents the charge transfer resistance, and σ w represents the Warburg coefficient, ω represents the angular frequency, and R is the ideal gas constant (8.314 Jmol -1 K -1), T represents temperature (K), n represents the number of electrons transferred per mol, and F is Faraday's constant (96500 C mol -1 ), and A is the surface area of ​​the electrode (cm 2 ) and C ion Li + Molar concentration (mol m -3 )). Warburg coefficient (σ w ) is Z' re 6B-6C, the Z from the highlighted area of ​​FIG. re Value 1 / w 1 / 2 By plotting against (angular frequency), we can obtain σ from the slope of the linear graph. w can be obtained (Figure 6C).

[0072] Cathode materials of embodiments herein may have improved σ-(Warburg coefficient) compared to cathode materials having the same cathode active material but with coatings formed by a process that includes calcination. Coatings formed by a process that includes calcination may result in thicker coatings and therefore tend to have larger σ-(Warburg coefficient) compared to coatings of embodiments herein.

[0073] In one embodiment, the cathode material may have a reversible discharge capacity under a voltage difference. In one aspect, the cathode material may be capable of shifting between a first crystal structure and a second crystal structure under a voltage difference, which may indicate the reversible discharge capacity of the cathode material. With reference to FIGS. 5B and 5C, a representative cathode material may be capable of shifting between a hexagonal crystal structure 500 and a monoclinic crystal structure 510 and may be capable of retaining the ability to shift between the two crystal structures 500 and 510 upon a first charge-discharge cycle and one or more additional charge-discharge cycles. Both crystal structures include a TM layer 504 and a Li layer 502. In certain aspects, the cathode material may be configured to retain a similar ability to shift between crystal structures upon a first charge-discharge cycle and one or more additional charge-discharge cycles. FIG. 5C includes an illustrative diagram of a differential capacity analysis of a representative cathode material S1. As illustrated, the cathode material S1 may be capable of retaining reversible discharge capacity for at least 1, at least 2, at least 3, at least 4, or at least 5 cycles.

[0074] In further embodiments, the cathode material may include a specific reversible discharge capacity under a voltage difference, which may facilitate improving the properties and / or performance of the cathode material. In further embodiments, the cathode material may include a specific coulombic efficiency under a voltage difference, which may facilitate improving the properties and / or performance of the cathode material. The coulombic efficiency may indicate the reversible discharge capacity of the cathode material. The coulombic efficiency may be determined by comparing the previously measured charge capacity C Ch(n) Measured discharge capacity C for cycle n dis(n) Those skilled in the art will appreciate that for ideal reversible discharge capacity, the coulombic efficiency should be about 100, and that if some irreversible discharge occurs, the coulombic efficiency may decrease.

[0075] In one embodiment, the cathode material may comprise a coulombic efficiency of at least 70% for at least one charge-recharge cycle, at least 75%, at least 78%, at least 80%, at least 85%, at least 88%, or at least 90% for at least one charge-recharge cycle. In certain examples, the coulombic efficiency may be close to 100% for at least one charge-recharge cycle, e.g., at least 93%, at least 95%, at least 97%, or at least 99%. In certain aspects, the coulombic efficiency may be about 100% for at least one charge-recharge cycle. In further aspects, the cathode material may comprise a coulombic efficiency of at least 70% for at least two charge-recharge cycles, at least three charge-recharge cycles, at least four charge-recharge cycles, or at least five charge-recharge cycles. In further embodiments, the cathode material can comprise a coulombic efficiency of at least 80% for at least one charge-recharge cycle, at least two charge-recharge cycles, at least three charge-recharge cycles, at least four charge-recharge cycles, or at least five charge-recharge cycles. In further embodiments, the cathode material can comprise a coulombic efficiency of at least 90% for at least one charge-discharge cycle, at least two charge-discharge cycles, at least three charge-discharge cycles, at least four charge-discharge cycles, or at least five charge-discharge cycles.

[0076] In further embodiments, the cathode material may facilitate improved electrolyte stability. Referring to Figure 5A, cathode material CS2, which has the same cathode active material as S1 but without the coating, is tested in a differential capacity analysis. A smaller peak can be observed between 3.4 V and 3.6 V, which may indicate irreversible discharge capacity of the cathode material and electrolyte degradation, despite the reversible discharge capacity indicated by the peak between 3.5 V and 3.9 V.

[0077] FIG. 4 includes an illustrative diagram of a process 400 for forming a cathode material. Process 400 can include treating a cathode active material with a fluorine-containing material. In an embodiment, the fluorine-containing material can include an organic material, an inorganic material, or any combination thereof. In certain embodiments, process 400 can include treating a cathode active material with an organic material that includes a fluorine-containing material. An exemplary organic material can include a fluorocarbon. Examples of fluorocarbons can include hydrofluoroolefins, chlorofluorocarbons, hydrofluorocarbons, or fluorocarbon compounds, or any combination thereof. Another fluorine-containing material can include F2. In a further example, a combination of two or more fluorine-containing materials can be utilized in process 400.

[0078] In one embodiment, treating the cathode active material with the fluorine-containing material can be carried out at a relatively low temperature. For example, the temperature can be less than 120°C, e.g., 90°C or less, 75°C or less, 60°C or less, 50°C or less, 40°C or less, 35°C or less, 30°C or less, 28°C or less, or 25°C or less. In another example, the temperature can be at least 15°C, at least 18°C, at least 20°C, at least 22°C, or at least 25°C. Furthermore, the temperature can be a range including any of the minimum and maximum values ​​described herein. In certain embodiments, treating the cathode active material with the fluorine-containing material can be carried out at a temperature in the range of at least 15°C to 50°C or less, or in the range of at least 18°C ​​to 35°C or less.

[0079] In certain embodiments, process 400 can be performed in a dry state. In one aspect, the material that may contact the cathode active material can be a dry material. For example, the material can be a solid, a gas, or any combination thereof. In a further example, process 400 can be free of materials that include a liquid phase.

[0080] In one embodiment, treating the cathode active material can be carried out for at least 2 minutes and up to 60 minutes, at least 5 minutes and up to 40 minutes, at least 8 minutes and up to 30 minutes, or at least 10 minutes and up to 26 minutes.

[0081] The process may proceed to block 404 and form a coating over at least a portion of the cathode active material. In one embodiment, forming the cathode material may include a chemical reaction between a fluorine-containing material and the cathode active material. In certain aspects, the reaction may include fluorination of the cathode active material. In further aspects, the reaction may facilitate deposition of a coating over at least a portion of the cathode active material.

[0082] In one embodiment, process 400 can include a chemical vapor deposition process for forming a coating over the cathode active material. In a further embodiment, process 400 can include treating the cathode active material with a fluorine-containing material using a plasma. In a particular example, a high-frequency plasma can be utilized with a controlled gas pressure. For example, the gas pressure can be controlled within a range of 0.1 to 1 mbar. In another particular example, the plasma can be a low-temperature plasma. In one example, the plasma can have a temperature of 100°C or less. In a particular example, the plasma can be less than 80°C, 70°C or less, 60°C or less, or 50°C or less. In a further example, the plasma can be excited by a frequency of 100 Hz to 1 GHz. In a particular embodiment, a plasma-enhanced chemical vapor deposition process can be used to form a cathode material including a coating over the cathode active material. In another embodiment, process 400 can include utilizing gas treatment.

[0083] In an exemplary embodiment, the process for forming the cathode material can be carried out at room temperature (i.e., 22-25°C). The cathode active material can be placed in a container and transferred to a reaction chamber. Plasma can be used to treat the cathode active material with a hydrofluoroolefin for 5-20 minutes to form the coated cathode active material. In particular, the plasma can be at a low temperature, such as below 80°C. In a more specific example, the plasma can include electrons with higher energy (i.e., temperature) than ions and neutral gas species. The non-equilibrium state of the plasma can promote the reaction to form the coating. In another specific example, the plasma can be applied at a low gas pressure, such as 0.1-1 mbar, to promote the non-equilibrium state and low temperature of the plasma.

[0084] In another exemplary embodiment, gas treatment using F2 can be performed. Specifically, the treatment can be performed at room temperature up to 150°C. The cathode active material can be exposed to 0.03 to 3 bar of F2 gas for 10 minutes to 6 hours to form a coating.

[0085] Many different aspects and embodiments are possible. Some of these aspects and embodiments are described herein. After reading this specification, those skilled in the art will understand that these aspects and embodiments are merely illustrative and do not limit the scope of the invention. An embodiment may follow any one or more of the embodiments listed below.

[0086] Embodiment Embodiment 1. A cathode material comprising a substrate comprising a cathode active material, wherein at least a portion of the substrate is CF x and a cathode material coated with a coating material comprising M2CO3, wherein M comprises an alkali metal.

[0087] Embodiment 2. The cathode material of embodiment 1, wherein M comprises Li, Na, or a combination thereof.

[0088] Embodiment 3. The cathode material of embodiment 1 or 2, wherein the coating material further comprises MF.

[0089] Embodiment 4. The cathode material of any one of Embodiments 1-3, wherein M comprises Li.

[0090] Embodiment 5. The cathode material of any one of embodiments 1-4, wherein the cathode active material comprises an oxide containing one or more metallic elements selected from the group consisting of alkali metals, 3d metals, 4d metals, 5d metals, rare earth metals, and alkaline earth metals.

[0091] Embodiment 6. The cathode material of any one of Embodiments 1 to 5, wherein the cathode active material comprises an alkali transition metal oxide.

[0092] Embodiment 7. The cathode material of embodiment 6, wherein the cathode active material comprises Li, Na, or a combination thereof.

[0093] Embodiment 8. The cathode material of embodiment 6 or 7, wherein the oxide comprises at least one 3d metal, including Ni.

[0094] Embodiment 9. The cathode material of embodiment 8, wherein the oxide comprises a Li—Ni—Mn oxide, optionally doped with another 3d metal.

[0095] Embodiment 10. The cathode material of any one of Embodiments 1-9, wherein the cathode active material comprises a Li—Ni—Mn—Co oxide.

[0096] Embodiment 11. The cathode material of any one of embodiments 1 to 10, wherein the substrate comprises particles comprising the cathode active material.

[0097] Embodiment 12. The cathode material of any one of embodiments 1 to 11, wherein the coating material is in the form of a thin film that covers at least a majority of the substrate.

[0098] Embodiment 13. The cathode material of any one of embodiments 1 to 12, wherein the substrate is in the form of a tape, a sheet, a film, a block, or any combination thereof.

[0099] Embodiment 14.2940Ωs -1 Below, 2800Ωs -1 Below, 2500Ωs -1 Below, 2200Ωs -1 Below, 2000Ωs -1 Below, 1800Ωs -1 Below, 1600Ωs -1 Below, 1490Ωs -1 or less, or 1350Ωs -1 14. The cathode material of any one of embodiments 1 to 13, comprising a σ-(Warburg coefficient) of:

[0100] Embodiment 15. At least 500 Ω -1 , at least 700Ωs -1 , at least 850Ωs -1 , at least 1000Ωs -1 , at least 1150Ωs -1 , at least 1300Ωs -1 , or at least 1400Ωs -1 15. The cathode material of any one of embodiments 1 to 14, comprising a σ-(Warburg coefficient) of

[0101] Embodiment 16. A CF of at least 3.6, at least 3.8, at least 4.1, at least 4.5, at least 4.8, at least 5.1, at least 5.3, at least 5.7, at least 5.9, at least 6.3, at least 6.7, at least 6.9, at least 7.2, at least 7.5, at least 7.8, at least 8.1, at least 8.3, at least 8.5, or at least 8.7. x 16. The cathode material of any one of embodiments 1 to 15, comprising a content ratio of M2CO3 to C1.

[0102] Embodiment 17.11.5 or less, 11.2 or less, 10.8 or less, 10.5 or less, 10.1 or less, 9.7 or less, 9.4 or less, 9.1 or less, 8.8 or less, 8.6 or less, or 8.3 or less, CF x17. The cathode material of any one of embodiments 1 to 16, comprising a content ratio of M2CO3 to C1.

[0103] Embodiment 18. The cathode material of any one of embodiments 1 to 17, comprising a relative content of M2CO3 of at least 0.4, at least 0.6, at least 0.7, at least 0.8, at least 0.9, or at least 1.0.

[0104] Embodiment 19. The cathode material of any one of embodiments 1 to 18, comprising a relative content of M2CO3 of 1.5 or less, 1.3 or less, 1.1 or less, 0.9 or less, or 0.8 or less.

[0105] Embodiment 20. A CF with a relative content of at least 0.05, at least 0.07, at least 0.09, at least 0.11, or at least 0.13. x 20. The cathode material of any one of embodiments 1 to 19, comprising:

[0106] Embodiment 21. A relative content of CF of 0.42 or less, 0.40 or less, 0.38 or less, 0.35 or less, 0.32 or less, 0.30 or less, 0.28 or less, 0.27 or less, 0.25 or less, 0.23 or less, 0.21 or less, 0.18 or less, 0.15 or less, or 0.13 or less. x 21. The cathode material of any one of embodiments 1 to 20, comprising:

[0107] Embodiment 22. The cathode material of any one of embodiments 1 to 21, comprising a content ratio of MF to M2CO3,C2 of at least 1.2, at least 1.4, at least 1.6, at least 1.8, at least 2.1, at least 2.3, at least 2.5, at least 2.7, at least 2.9, at least 3.0, or at least 3.2.

[0108] Embodiment 23. The cathode material of any one of embodiments 1 to 22, comprising a content ratio of MF to M2CO3, C2, of 6.4 or less, 6.1 or less, 5.8 or less, 5.5 or less, 5.2 or less, 4.9 or less, 4.6 or less, 4.3 or less, 4.1 or less, 3.8 or less, 3.5 or less, 3.2 or less, 3.1 or less, or 2.9 or less.

[0109] Embodiment 24. A CF of at least 6.3, at least 7.8, at least 9.2, at least 10.5, at least 11.1, at least 12.3, at least 14.5, at least 15.2, at least 16.9, at least 18.0, at least 19.5, at least 21.5, at least 23.8, at least 24.5, at least 25.8, or at least 26.2. x 24. The cathode material of any one of the preceding embodiments, comprising a content ratio of MF to C3.

[0110] CF of 25.35.4 or less, 34.1 or less, 32.8 or less, 31.5 or less, 30.2 or less, 28.9 or less, 28.6 or less, 27.3 or less, 26.1 or less, 25.8 or less, or 24.5 or less x 25. The cathode material of any one of the preceding embodiments, comprising a content ratio of MF to C3.

[0111] Embodiment 26. The cathode material of any one of embodiments 1 to 25, comprising a relative content of MF of at least 1.2, at least 1.4, at least 1.7, at least 1.9, at least 2.1, at least 2.3, at least 2.5, at least 2.7, at least 2.9, at least 3.0, or at least 3.2.

[0112] Embodiment 27. The cathode material of any one of embodiments 1 to 26, comprising a relative content of MF of 6.4 or less, 6.1 or less, 5.8 or less, 5.5 or less, 5.2 or less, 4.9 or less, 4.6 or less, 4.2 or less, 3.9 or less, 3.7 or less, 3.5 or less, 3.1 or less, or 3.0 or less.

[0113] Embodiment 28. A multilayer structure comprising a cathode layer overlying an electrolyte layer, the cathode layer comprising the cathode material of any one of claims 1 to 27.

[0114] Embodiment 29. The multilayer structure of embodiment 28, wherein the cathode layer is adjacent to the electrolyte layer and the coating material is in direct contact with the electrolyte layer.

[0115] Embodiment 30. The multilayer structure of embodiment 28 or 29, wherein the electrolyte layer comprises a solid electrolyte material, and the solid electrolyte material comprises a halide material.

[0116] Embodiment 31. A material comprising the cathode material of any one of embodiments 1 to 27 and a solid electrolyte material comprising a halide material.

[0117] Embodiment 32. The halide material is selected from the group consisting of F, Cl, Br, and I, and Li 3-x-f M f RE 1-y Me k y (Cl 1-u-p-q Br u F p I q ) 6-x+y*(k-3) and a halide anion represented by During the ceremony, -1<=x<=1, 0<=y<=1, 0<=u<1, 0<=p<=1 / 3, 0<=q<=1 / 6, 0<(u+p+q)<1, 0<=f<=0.3, M is at least one alkali metal element other than Li; RE is a rare earth element, k is the valence of Me, 32. The multilayer structure or material of any one of embodiments 30-31, wherein Me is at least one element selected from the group consisting of Group IIIB elements, Group IVB elements, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Al, Sn, Pb, Bi, Sb, Mg, Ca, Ga, and Ge, and Me is different from RE.

[0118] Embodiment 33. The multilayer structure or material of any one of embodiments 28-32, wherein the electrolyte material comprises a halide material comprising at least two halide anions selected from the group consisting of F, Cl, Br, and I.

[0119] Embodiment 34. The halide material comprises, based on the total weight of the halide material: one or more water-insoluble impurity phases with a total content of less than 0.11% by weight; a total content of binary halide phases of not more than 10% by weight, 6% by weight or less of a ternary halide phase, or 34. The multilayer structure or material of any one of embodiments 30 to 33, comprising at least one of any combination thereof.

[0120] Embodiment 35. The halide material is Li 3-x RE 1-y Me k y (Cl 1-u Br u ) 6-x+y*(k-3) 35. The multilayer structure of any one of embodiments 30 to 34, wherein u is represented by the formula:

[0121] Embodiment 36. The halide material is Li a M a Me b Me' b’ X c X' c’ and the halide material is represented by (b / (b+b')) t * 0.84 t * ​1.16 (in the formula, (b / (b+b')) t corresponds to the crystallographic phase transition on the crystallographic phase diagram at temperatures between 20°C and 25°C), (c / (c+c')) t * 0.84 <c / (c+c’)<(c / (c+c’)) t * 1.16 (in the formula, (c / (c+c')) t corresponds to a crystallographic phase transition on the crystallographic phase diagram at temperatures between 20°C and 25°C), or (a / (a+a')) t * 0.84 t * 1.16 (wherein, (a / (a+a')) t corresponds to the crystallographic phase transition on the crystallographic phase diagram at temperatures between 20°C and 25°C) 36. The multilayer structure or material of any one of embodiments 30 to 35, having a crystallographic phase transition in the stoichiometric range of:

[0122] Embodiment 37. The multilayer structure or material of any one of embodiments 1 to 36, wherein the cathode material is capable of shifting between a hexagonal and a monoclinic crystal structure under a voltage difference.

[0123] Embodiment 38. The multilayer structure or material of any one of embodiments 1 to 37, wherein the cathode material comprises a reversible discharge capacity under a voltage difference, and wherein the cathode material comprises a coulombic efficiency of at least 70%, at least 75%, at least 78%, at least 80%, at least 85%, at least 88%, at least 90%, near 100%, or 100%.

[0124] Embodiment 39. A method comprising treating a cathode active material with an organic material comprising a fluorine-containing material at a temperature less than 120°C.

[0125] Embodiment 40. The method of embodiment 39, wherein treating the cathode active material is carried out dry.

[0126] ​Embodiment 41. The method of embodiment 39 or 40, wherein the fluorine-containing material comprises an organic material, an inorganic material, or any combination thereof.

[0127] Embodiment 42. The method of any one of embodiments 39-41, wherein the fluorine-containing material comprises a fluorocarbon.

[0128] Embodiment 43. The method of any one of embodiments 39-42, wherein the fluorine-containing material comprises a hydrofluoroolefin, a chlorofluorocarbon, a hydrofluorocarbon, or a fluorocarbon compound, or any combination thereof.

[0129] Embodiment 44. The method of any one of embodiments 39-41, wherein the fluorine-containing material comprises F2.

[0130] Embodiment 45. The method of any one of embodiments 39-44, comprising treating the cathode active material using a plasma.

[0131] Embodiment 46. The method of embodiment 45, wherein the plasma is excited by a frequency of 100 Hz to 1 Ghz.

[0132] Embodiment 47. The method of embodiment 45 or 46, wherein the plasma is applied at a gas pressure of at least 0.1 mbar and at most 1 mbar.

[0133] Embodiment 48. The method of any one of embodiments 39-47, wherein treating the cathode active material is carried out for at least 2 minutes and no more than 60 minutes, at least 5 minutes and no more than 40 minutes, at least 8 minutes and no more than 30 minutes, or at least 10 minutes and no more than 26 minutes.

[0134] Embodiment 49. The method of any one of embodiments 39-48, wherein treating the cathode active material is carried out at a temperature of 90°C or less, 75°C or less, 60°C or less, 50°C or less, 40°C or less, 30°C or less, or 28°C or less.

[0135] Embodiment 50. The method of any one of embodiments 39-49, wherein treating the cathode active material is carried out at a temperature of at least 15°C, at least 20°C, or at least 22°C.

[0136] Embodiment 51. The method of any one of embodiments 39-50, wherein treating the cathode active material comprises a chemical vapor deposition process.

[0137] Embodiment 52. The method of any one of embodiments 39-51, wherein treating the cathode active material comprises a plasma-enhanced chemical vapor deposition process. [Example]

[0138] Example 1 The cathode active material NMC622 is fluorinated by using hydrofluoroolefin and plasma enhanced chemical vapor deposition (PE-CVD) to form coated NMC622 according to embodiments herein. Uncoated NMC622 and coated NMC622 were fluorinated using LiY(Cl) 0.65 Br 0.35 )6 and conductive carbon were pressed into a pellet, and a lithium foil anode and LiY(Cl 0.65 Br 0.35 The pressed pellets of 6 were used as cathodes in cells containing electrolytes. Cell 1 contained uncoated NMC622. Cell 2 contained coated NMC622. XPS was used to characterize the CF x The coated NMC622 was identified as containing a coating containing fluorine, LiF, and Li2CO3, while the uncoated NMC622 did not contain any fluorine-containing species. The cathode was a cathode material and Li3Y(Cl 0.65 Br 0.35 )6, 60 wt. % of each cathode material, 40 wt. % of LiY(Cl 0.65 Br 0.35 )6, and 0.5 wt. % conductive carbon.

[0139] The specific capacities of the battery unit cells 1 and 2 were tested at voltages of 3 V to 4.2 V (vs. Li / Li + Summary data for battery unit cells 1 and 2 are included in Tables 1 and 2, respectively.

[0140] [Table 1]

[0141] [Table 2]

[0142] Battery unit cell 2 showed improved maximum charge capacity and maximum discharge capacity for all charge-discharge cycles, as well as improved Coulombic efficiency (CE%), compared to battery unit cell 1 in cycle 1. The low Coulombic efficiency of the cathode material in cell 1 indicated electrolyte degradation and irreversible discharge during lithiation and delithiation. The high Coulombic efficiency of the coated cathode material in cell 2 indicated improved reversible discharge capacity of the coated cathode material and significantly reduced electrolyte degradation.

[0143] Example 2 Cathode active material NMC622 is treated with hydrofluoroolefin (HFO) by using plasma-enhanced chemical vapor deposition (PE-CVD) to form coated NMC622 according to an embodiment of the present disclosure. The plasma treatment time is varied to form different coated NMC622 samples. Coated NMC622 sample S3 is formed by a 5-minute plasma treatment. Coated NMC622 sample S4 is formed by a 10-minute plasma treatment. Coated NMC622 sample S5 is formed by a 20-minute plasma treatment. As in Example 1, XPS is used to characterize the coated NMC622 samples, including the coating containing CF1, LiF, and Li2CO3.

[0144] The uncoated NMC622 and all coated NMC622 samples were used to form cathodes in the same manner as in Example 1, and lithium foil anodes and Li3Y(Cl) 0.65 Br 0.35 )6 pressed pellets were used as cathodes in cells containing electrolytes. Cell 3 contains coated NMC622 S3. Cell 4 contains coated NMC622 S4. Cell 5 contains coated NMC622 S5. Cell 6 is formed using uncoated NMC622. The cathode is formed using a mixture of cathode material and Li3Y(Cl). 0.65 Br 0.35 )6, 60 wt. % of each cathode material, 40 wt. % of LiY(Cl 0.65 Br 0.35 )6, and 0.5 wt. % conductive carbon.

[0145] The specific capacity of the battery unit cells was tested and is illustrated in Figure 5A (battery unit cell 6) and Figure 5C (battery unit cell 4). It can be observed that the electrolyte degradation suggested by the irreversible discharge capacity illustrated in Figure 5A is suppressed by coated Sample 6, considering the absence of a smaller peak between 3.4 V and 3.6 V in Figure 5C. As illustrated in Figure 5A, the smaller peak between 3.4 V and 3.6 V indicates irreversible discharge capacity and electrolyte degradation.

[0146] Differential capacity analysis was performed on the battery unit cells for up to five charge-discharge cycles and is summarized in FIG. 5D. As illustrated in FIG. 5D, battery unit cell 4 showed improved initial capacity (cycle 1) and specific capacity with increasing cycle number compared to battery unit cell 6. The data further suggest a capacity degradation of battery unit cell 6 and an improved capacity retention of unit cell 4 with increasing cycle number.

[0147] FIG. 6A includes a plot of specific capacity versus cycle number for battery unit cells 3-5. It can be observed that battery unit cells 3-5 all exhibited improved specific capacity and capacity retention over the test cycles. Unit cell 4 may have a further improved specific capacity compared to unit cells 3 and 5, and unit cell 3 may have an improved specific capacity over unit cell 5. Unit cell 5 does not exhibit an improvement in specific capacity over the test cycles, but has improved capacity retention, compared to unit cell 6 (not shown).

[0148] Figure 6B shows the -Z curves of battery unit cells 3 to 5 using linear frequencies. lmag vs. Z re 6B includes a plot of ω. As illustrated, cathode material S4 has a higher ion diffusion Warburg impedance than cathode material S3, which in turn has a higher Warburg impedance than cathode material S4. The Z values ​​in the highlighted region of FIG. 6B are plotted against ω. -1 / 2 It is extracted and plotted against ω -1 / 2 Z for re The plot of is illustrated in Figure 6C. The data shows that cathode material S5 has the lowest Li compared to cathode materials S3 and S4. + The cathode material S4 may have a higher Li ion diffusion rate than the cathode material S3. + This suggests that the ionic diffusion rate may be higher.

[0149] The σ- (Warburg coefficients) of cathode materials S3-5 were calculated according to embodiments herein and are included in Table 3 below.

[0150] [Table 3]

[0151] CF of cathode materials S3 to S5 xThe relative contents of fluoride, LiF, and Li2CO3 are tested by performing XPS on samples with sample sizes statistically representative of Samples S3-5, as described in embodiments herein. The relative contents (relative to the Ni content) are shown in Table 4 below. Fluoride, fluorocarbons, and LiF are not detected in uncoated NMC622 samples using high-resolution XPS spectra of F 1s.

[0152] The concentrations of organic and inorganic fluorides in samples S3 to S5 were evaluated and determined based on the ratio of the organic fluoride (fluorocarbon) concentration to the inorganic fluoride (LiF) concentration obtained by using high-resolution XPS spectra of F 1s, as well as the total concentrations of organic and inorganic fluorides obtained by ion chromatography analysis. Organic fluorides have a binding energy peak at 689 eV, and inorganic fluorides have a binding energy peak between 681 and 682 eV. The concentrations are shown in Table 5. The total concentration is the weight of all fluorides relative to the weight of the sample, and the concentrations of organic and inorganic fluorides are the respective weights relative to the weight of the sample.

[0153] [Table 4]

[0154] [Table 5]

[0155] Example 3 The cathode material set of Sample S4 in Example 2 was heated at 500°C to remove carbon species, forming Sample S9. Sample S9 was analyzed by high-resolution XPS spectroscopy of F 1s, and it was confirmed that no fluorocarbons were detected. Battery unit cell 9 was formed in the same manner as described in Example 2, except that the cathode was formed using Sample S9.

[0156] 7 includes plots of specific capacity versus cycle number for battery unit cells 4 and 9. It can be observed that battery unit cell 9 has a lower specific capacity compared to battery unit cell 4, which may suggest that fluorocarbons may promote improvement of battery cell performance.

[0157] Example 4 Cathode active material NMC811(LiNi 0.8 Mn 0.1 Co 0.1 O2) is fluorinated by using hydrofluoroolefin and plasma-enhanced chemical vapor deposition (PE-CVD) according to embodiments herein to form coated NMC811. Uncoated NMC811 and coated NMC811 were fluorinated with Li3Y(Cl 0.65 Br 0.35 )6 and conductive carbon were pressed into a pellet, and a lithium foil anode and LiY(Cl 0.65 Br 0.35 )6 pressed pellets were used as cathodes in cells containing electrolytes. Cell sample S10 contained uncoated NMC811. Cell sample S11 contained coated NMC811. The cathodes were made of a mixture of cathode material and Li3Y(Cl 0.65 Br 0.35 )6, 60 wt. % of each cathode material, 40 wt. % of LiY(Cl 0.65 Br 0.35 )6, and 0.5 wt. % conductive carbon.

[0158] 8 includes plots of specific capacity versus voltage for battery unit cell samples S10 and S11. Sample S11 exhibits better specific capacity stability over the tested voltages than sample S10.

[0159] Benefits, other advantages, and solutions to problems have been described above with respect to specific embodiments. However, benefits, advantages, solutions to problems, and any features that may provide or enhance any benefit, advantage, or solution should not be construed as critical, necessary, or essential features of any or all claims. References herein to a material containing one or more components may be interpreted to include at least one embodiment in which the material consists essentially of the specified component or components. The term "consisting essentially of" is to be interpreted to include compositions that include the specified components and exclude all other materials except for minor contents (e.g., impurity contents) that do not significantly alter the properties of the material. Furthermore, references to values ​​stated in ranges include any and all values ​​within that range. Additionally, or alternatively, in certain non-limiting embodiments, any of the compositions specified herein may be essentially free of materials not explicitly disclosed. It will be understood that embodiments herein include ranges of content of certain components within a material, and that the content of components within a given material totals 100%.

[0160] The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may be provided in combination in a single embodiment, and conversely, various features that are described for brevity in the context of a single embodiment may also be provided separately or in any subcombination. Furthermore, references to values ​​described in ranges include any and all values ​​within that range. Many other embodiments may become apparent to those skilled in the art only after reading this specification. Other embodiments may be utilized and derived from the present disclosure, such that structural substitutions, logical substitutions, or other changes may be made without departing from the scope of the present disclosure. Accordingly, the present disclosure should be considered illustrative, not restrictive.

Claims

1. A cathode material comprising a substrate comprising a cathode active material, at least a portion of the substrate comprising a fluorinated carbon and M ２ CO ３ wherein M comprises an alkali metal, including Li, Na, or a combination thereof.

2. 10. The cathode material of claim 1, wherein the active cathode material comprises an alkali transition metal oxide.

3. 10. The cathode material of claim 1, wherein the coating material further comprises MF.

4. The cathode material of any one of claims 1 to 3, wherein M comprises Li.

5. 4. The cathode material of claim 1, wherein the active cathode material comprises a Li—Ni—Mn oxide, optionally doped with another 3d metal.

6. The cathode material of any one of claims 1 to 3, wherein the substrate comprises particles comprising the active cathode material.

7. 4. The cathode material of claim 1, wherein the coating material is in the form of a thin film covering at least a majority of the substrate, and the substrate is in the form of a tape, a sheet, a film, a block, or any combination thereof.

8. The fluorocarbon is CF １ The cathode material of any one of claims 1 to 3, comprising:

9. Fluorinated carbon C of at least 3.6 and not more than 11.5 １ M against ２ CO ３ The cathode material according to any one of claims 1 to 3, comprising a content ratio of:

10. 4. The cathode material of claim 1, comprising a total concentration of fluoride less than 805 μg / g, inorganic fluoride greater than 202.3 μg / g, or a combination thereof, based on the weight of the active cathode material.

11. A multilayer structure comprising a cathode layer overlying an electrolyte layer, said cathode layer comprising the cathode material of claim 1.

12. At least a portion of the coating material is in direct contact with the electrolyte layer, and the electrolyte material is ３－ｘ－ｆ M ｆ RE １－ｙ Me ｋ ｙ (Cl １－ｕ－ｐ－ｑ Br ｕ F ｐ I ｑ ) ６－ｘ＋ｙ＊（ｋ－３） The solid electrolyte material includes a halide-based material represented by During the ceremony, −1≦x≦1, 0≦y≦1, 0≦u<1, 0≦p≦1 / 3, 0≦q≦1 / 6, 0<(u+p+q)<1, 0≦f≦0.3, 2≦k≦6, M is at least one alkali metal element other than Li; RE is a rare earth element, k is the valence of Me; 12. The multilayer structure of claim 11, wherein Me is at least one element selected from the group consisting of Group IIIB elements, Group IVB elements, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Al, Sn, Pb, Bi, Sb, Mg, Ca, Ga, and Ge, and Me is different from RE.

13. The multilayer structure of claim 12 wherein the halide material comprises at least two halogens.

14. The cathode material of claim 1 and Li ３－ｘ－ｆ M ｆ RE １－ｙ Me ｋ ｙ (Cl １－ｕ－ｐ－ｑ Br ｕ F ｐ I ｑ ) ６－ｘ＋ｙ＊（ｋ－３） is represented by During the ceremony, −1≦x≦1, 0≦y≦1, 0≦u<1, 0≦p≦1 / 3, 0≦q≦1 / 6, 0<(u+p+q)<1, 0≦f≦0.3, 2≦k≦6, M is at least one alkali metal element other than Li; RE is a rare earth element, k is the valence of Me; a solid electrolyte material comprising a halide material, wherein Me is at least one element selected from the group consisting of a Group IIIB element, a Group IVB element, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Al, Sn, Pb, Bi, Sb, Mg, Ca, Ga, and Ge, and Me is different from RE.

15. 1. A method comprising: treating a cathode active material with an organic material comprising a fluorine-containing material at a temperature less than 120° C., wherein the fluorine-containing material comprises a hydrofluoroolefin, a chlorofluorocarbon, a hydrofluorocarbon, or a fluorocarbon compound, or any combination thereof.

Images