Abstract: Provided is a sulfide-based solid electrolyte which is capable of suppressing the generation of hydrogen sulfide caused by reaction with moisture even when in contact with dry air in a dry room or the like, and capable of maintaining lithium ion conductivity. Proposed is a sulfide-based solid electrolyte for a lithium secondary battery, wherein the surface of a compound containing lithium, phosphorus, sulfur, and halogen, and having a cubic argyrodite-type crystal structure is coated with a compound containing lithium, phosphorus, and sulfur, and having a non-argyrodite-type crystal structure.

Abstract: A sulfide-based solid electrolyte particle having a crystal phase of a cubic argyrodite-type crystal structure composed of Li, P, S and a halogen (Ha. The proposed sulfide-based solid electrolyte particle has a feature such that the ratio (ZHa2/ZHa1) of an element ratio ZHa2 of the halogen (Ha) at the position of 5 nm in depth from the particle surface to an element ratio ZHa1 of the halogen (Ha) at the position of 100 nm in depth from the particle surface is 0.5 or lower, as measured by XPS; and the ratio (ZO2/ZA2) of an element ratio ZO2 of oxygen to the total ZA2 of element ratios of phosphorus (P), sulfur (S), oxygen (O) and the halogen (Ha) at the position of 5 nm in depth from the particle surface is 0.5 or higher, as measured by XPS.

Abstract: A sulfide solid electrolyte is provided having peak A at 2?=20.7°±0.5° in an X-ray diffraction pattern obtained by performing X-ray diffraction measurement using CuK?1 radiation. It is preferable that the sulfide solid electrolyte has peak B at 2?=25.4°±1.0° in the X-ray diffraction pattern obtained by performing X-ray diffraction measurement using CuK?1 radiation. It is also preferable that the value of the ratio of IA to IB, IA/IB, is more than 0 and 0.7 or less, where IA is the intensity of peak A and IB is the intensity of peak B. It is also preferable that the sulfide solid electrolyte has peak C at 2?=22.0°±0.5° in the X-ray diffraction pattern obtained by performing X-ray diffraction measurement using CuK?1 radiation.

Abstract: A sulfide solid electrolyte is provided having peak A at 2?=20.7°±0.5° in an X-ray diffraction pattern obtained by performing X-ray diffraction measurement using CuK?1 radiation. It is preferable that the sulfide solid electrolyte has peak B at 2?=25.4°±1.0° in the X-ray diffraction pattern obtained by performing X-ray diffraction measurement using CuK?1 radiation. It is also preferable that the value of the ratio of IA to IB, IA/IB, is more than 0 and 0.7 or less, where IA is the intensity of peak A and IB is the intensity of peak B. It is also preferable that the sulfide solid electrolyte has peak C at 2?=22.0°±0.5° in the X-ray diffraction pattern obtained by performing X-ray diffraction measurement using CuK?1 radiation.

Abstract: A sulfide solid electrolyte is provided having: diffraction peak A observed within a range of 2?=20.0° to 24.0°; and diffraction peak B observed within a range of 2?=24.4° to 26.4°, diffraction peak A and diffraction peak B being observed by performing X-ray diffraction measurement using CuK?1 radiation, and the ratio of IA to IB, IA/IB, being 2.0 or less, wherein IA is an intensity of diffraction peak A and IB is an intensity of diffraction peak B. Preferably, the sulfide solid electrolyte contains elemental lithium, elemental phosphorus, elemental sulfur, and an elemental halogen. It is also preferable that the sulfide solid electrolyte has an argyrodite-type crystal structure. It is also preferable that the sulfide solid electrolyte contains a lithium halide hydrate.

Abstract: A sulfide solid electrolyte is provided that can reduce the reaction resistance between an active material and the sulfide solid electrolyte. The sulfide solid electrolyte has a weight loss rate of 2.6% or more and 9.6% or less, the percentage of weight loss rate being measured by heating the sulfide solid from 25° C. to 400° C. at a heating rate of 10° C./min in thermogravimetry. It is preferable that this sulfide solid electrolyte contains elemental lithium (Li), elemental phosphorus (P), elemental sulfur (S), an elemental halogen (X), and elemental oxygen (O). Also, this sulfide solid electrolyte is favorably produced by mixing a sulfide solid electrolyte with a compound that contains water of crystallization.

Abstract: A sulfide-based solid electrolyte particle having a crystal phase of a cubic argyrodite-type crystal structure composed of Li, P, S and a halogen (Ha), wherein good contact between the sulfide-based solid electrolyte particles and positive or negative electrode active material particles is secured and improvements in the rate characteristic and the cycle characteristic are attained. The ratio (ZHa2/ZHa1) of an element ratio ZHa2 of the halogen (Ha) at the position of 5 nm in depth from the particle surface to an element ratio ZHa1 of the halogen (Ha) at the position of 100 nm in depth from the particle surface is 0.5 or lower and the ratio (ZO2/ZA2) of an element ratio ZO2 of oxygen to the total ZA2 of element ratios of P, S, O, and the halogen (Ha) at the position of 5 nm in depth from the particle surface is 0.5 or higher, as measured by XPS.

Abstract: As a novel sulfide compound having a low elastic modulus while retaining high ion conductivity, a sulfide compound for a solid electrolyte of a lithium secondary battery that includes a crystal phase of a cubic argyrodite type crystal structure, and is represented by the compositional formula: Li7?xPS6?xClyBrz, wherein x in the compositional formula satisfies x=y+z and 1.0<x?1.8, and a ratio, z/y, of the molar ratio of Br to the molar ratio of Cl is from 0.1 to 10.0.

Abstract: As a novel sulfide compound having a low elastic modulus while retaining the high ion conductivity, a sulfide compound for a solid electrolyte of a lithium secondary battery that includes a crystal phase of a cubic argyrodite type crystal structure, and is represented by the compositional formula: Li7?xPS6?xClyBrz, wherein x in the compositional formula satisfies x=y+z and 1.0<x?1.8, and a ratio (z/y) of the molar ratio of Br to the molar ratio of Cl is from 0.1 to 10.0 is proposed.

Abstract: A novel sulfide solid electrolyte containing Li, P, S, and a halogen, which can be used as a solid electrolyte for a lithium secondary battery or the like, and is able to suppress the generation of a hydrogen sulfide gas even when exposed to moisture in the atmosphere. The sulfide solid electrolyte comprises a crystal phase or a compound having an argyrodite-type structure and containing Li, P, S, and a halogen; and a compound composed of Li, Cl, and Br and having a peak at each position of 2?=29.1°±0.5° and 33.7°±0.5° in an X-ray diffraction pattern.

Abstract: A novel sulfide solid electrolyte containing Li, P, S, and a halogen, which can be used as a solid electrolyte for a lithium secondary battery or the like, and is able to suppress the generation of a hydrogen sulfide gas even when exposed to moisture in the atmosphere. The sulfide solid electrolyte comprises a crystal phase or a compound having an argyrodite-type structure and containing Li, P, S, and a halogen; and a compound composed of Li, Cl, and Br and having a peak at each position of 2?=29.1°±0.5° and 33.7°±0.5° in an X-ray diffraction pattern.

Abstract: A sulfide-based solid electrolyte particle having a crystal phase of a cubic argyrodite-type crystal structure composed of Li, P, S and a halogen (Ha. The proposed sulfide-based solid electrolyte particle has a feature such that the ratio (ZHa2/ZHa1) of an element ratio ZHa2 of the halogen (Ha) at the position of 5 nm in depth from the particle surface to an element ratio ZHa1 of the halogen (Ha) at the position of 100 nm in depth from the particle surface is 0.5 or lower, as measured by XPS; and the ratio (ZO2/ZA2) of an element ratio ZO2 of oxygen to the total ZA2 of element ratios of phosphorus (P), sulfur (S), oxygen (O) and the halogen (Ha) at the position of 5 nm in depth from the particle surface is 0.5 or higher, as measured by XPS.

Abstract: As a novel sulfide compound having a low elastic modulus while retaining the high ion conductivity, a sulfide compound for a solid electrolyte of a lithium secondary battery that includes a crystal phase of a cubic argyrodite type crystal structure, and is represented by the compositional formula: Li7?xPS6?xClyBrz, wherein x in the compositional formula satisfies x=y+z and 1.0<x?1.8, and a ratio (z/y) of the molar ratio of Br to the molar ratio of Cl is from 0.1 to 10.0 is proposed.

Abstract: Provided is a sulfide-based solid electrolyte which is capable of suppressing the generation of hydrogen sulfide caused by reaction with moisture even when in contact with dry air in a dry room or the like, and capable of maintaining lithium ion conductivity. Proposed is a sulfide-based solid electrolyte for a lithium secondary battery, wherein the surface of a compound containing lithium, phosphorus, sulfur, and halogen, and having a cubic argyrodite-type crystal structure is coated with a compound containing lithium, phosphorus, and sulfur, and having a non-argyrodite-type crystal structure.

Abstract: Proposed is a new sulfide-based solid electrolyte for lithium ion batteries, the sulfide-based solid electrolyte relating to a compound that has a cubic argyrodite type crystal structure and is represented by Li7-x-2yPS6-x-yClx, and having excellent water resistance and oxidation resistance. Proposed is a sulfide-based solid electrolyte for lithium ion batteries, the sulfide-based solid electrolyte containing a compound that has a cubic argyrodite type crystal structure and is represented by compositional formula (1): Li7-x-2yPS6-x-yClx, in which compositional formula, conditions: 0.8?x?1.7 and 0<y??0.25x+0.5 are satisfied.

Abstract: Relating to a sulfide-based solid electrolyte compound for lithium ion batteries which has a cubic argyrodite-type crystal structure, to provide a compound which can suppress a generation amount of hydrogen sulfide when being left to stand in the air and which can maintain high conductivity even when being left to stand in dry air. Proposed is a sulfide-based solid electrolyte compound for lithium ion batteries containing a crystal phase of the cubic argyrodite-type crystal structure and represented by a composition formula (1): Li7?x+yPS6?xClx+y, wherein x and y in the composition formula (1) satisfy 0.05?y?0.9 and ?3.0x+1.8?y??3.0x+5.7.

Abstract: Relating to a sulfide-based solid electrolyte compound for lithium ion batteries which has a cubic argyrodite-type crystal structure, to provide a compound which can suppress a generation amount of hydrogen sulfide when being left to stand in the air and which can maintain high conductivity even when being left to stand in dry air. Proposed is a sulfide-based solid electrolyte compound for lithium ion batteries containing a crystal phase of the cubic argyrodite-type crystal structure and represented by a composition formula (1): Li7-x+yPS6-xClx+y, wherein x and y in the composition formula (1) satisfy 0.05?y?0.9 and ?3.0x+1.8?y??3.0x+5.7.

Abstract: Provided is a solid electrolyte with which charge/discharge efficiency and cycle characteristics can be increased by reducing the electron conductivity of a compound which has a cubic crystal structure belonging to a space group F-43m, and is represented by Compositional Formula: Li7-xPS6-xHax (Ha is Cl or Br). Proposed is a sulfide-based solid electrolyte for a lithium ion battery, which includes a compound having a cubic crystal structure belonging to a space group F-43m, and being represented by Compositional Formula: Li7-xPS6-xHax (Ha is Cl or Br), in which x in the above Compositional Formula is 0.2 to 1.8, and the value of the lightness L* thereof in the L*a*b* color system is 60.0 or more.

Abstract: Proposed is a new sulfide-based solid electrolyte for lithium ion batteries, the sulfide-based solid electrolyte relating to a compound that has a cubic argyrodite type crystal structure and is represented by Li7-x-2yPS6-x-yClx, and having excellent water resistance and oxidation resistance. Proposed is a sulfide-based solid electrolyte for lithium ion batteries, the sulfide-based solid electrolyte containing a compound that has a cubic argyrodite type crystal structure and is represented by compositional formula (1) : Li7-x-2yPS6-x-yClx, in which compositional formula, conditions: 0.8 ?x?1.7 and 0<y??0.25x+0.5 are satisfied.

Abstract: Provided is a solid electrolyte with which charge/discharge efficiency and cycle characteristics can be increased by reducing the electron conductivity of a compound which has a cubic crystal structure belonging to a space group F-43m, and is represented by Compositional Formula: Li7-xPS6-xHax (Ha is Cl or Br). Proposed is a sulfide-based solid electrolyte for a lithium ion battery, which includes a compound having a cubic crystal structure belonging to a space group F-43m, and being represented by Compositional Formula: Li7-xPS6-xHax (Ha is Cl or Br), in which x in the above Compositional Formula is 0.2 to 1.8, and the value of the lightness L* thereof in the L*a*b* color system is 60.0 or more.