An object of the present invention is to provide a sulfide solid electrolyte having a reduced specific surface area; an electrode composite material, a slurry and a solid battery, in each of which the sulfide solid electrolyte is used; and a method of producing the sulfide solid electrolyte, and the present invention provides a sulfide solid electrolyte containing lithium (Li), phosphorus (P) and sulfur (S) elements, and also containing a crystal phase having peaks at positions of 2θ=23.2°±1.00° and 29.2°±0.500° in an X-ray diffraction pattern measured with CuKα1 radiation.

There is provided a sulfide solid electrolyte containing elemental lithium (Li), elemental phosphorus (P), elemental sulfur (S), and an elemental halogen (X). The mole ratio of the elemental lithium (Li) to the elemental phosphorus (P), Li/P, satisfies 3.7<Li/P<5.4. The mole ratio of the elemental sulfur (S) to the elemental phosphorus (P), S/P, satisfies 3.9<S/P<4.1. The mole ratio of the elemental halogen (X) to the elemental phosphorus (P), X/P, satisfies 0.7<X/P<2.4. The sulfide solid electrolyte includes a crystalline phase having an argyrodite-type crystal structure.

A lithium-sulfur battery includes a casing, a top lid circumferentially welded to the casing, a negative contact surface positioned opposite the top lid, a positive terminal disposed within the casing, welded to the top lid, and configured as a mandrel, a glass insulator circumferentially wound around the mandrel, and a jelly roll including at least an anode and a cathode wound around the mandrel. The jelly roll may also include a top surface not in contact with the top lid, a bottom surface partially in contact with the negative contact surface, and partially in contact with a plurality of non-hollow carbonaceous spherical particles disposed between the bottom surface of the jelly roll and the negative contact surface. At least some of the non-hollow carbonaceous spherical particles may provide one or more electrically-conductive pathways between the bottom surface and the negative contact surface.

The propose method of manufacturing a solid-state lithium battery consists of preparing an anode coated with a solid-state electrolyte precursor and a cathode unit coated with solid-state electrolyte, both precursors containing a predetermined amount of a redundant water. The thus prepared anode unit and cathode unit are pressed to each other through their respective electrolyte precursor layers in a closed chamber at a predetermined elevated temperature and under a predetermined mechanical pressure, whereby an integral pre-final solid-state battery unit is formed. The manufacture of the battery is completed by inserting the prefinal product into a casing that leaves parts of the metal current collectors of the prefinal product exposed for use as a battery anode and a battery cathode.

Provided are a binder composition for an all-solid-state secondary battery with which it is possible to obtain an all-solid-state secondary battery that has good battery characteristics and for which processability during all-solid-state secondary battery production is excellent, a slurry composition for an all-solid-state secondary battery that contains this binder composition for an all-solid-state secondary battery, a functional layer for an all-solid-state secondary battery that is formed from this slurry composition for an all-solid-state secondary battery, and an all-solid-state secondary battery that includes this functional layer for an all-solid-state secondary battery. The binder composition for an all-solid-state secondary battery contains a polymer, an unsaturated acid metal salt monomer, and a solvent. The unsaturated acid metal salt monomer includes a divalent metal.

The solid electrolyte material consists essentially of Li, Ti, M, and F. Here, M is at least one selected from the group consisting of Al and Y.

A method of treating the surface of a positive electrode active material that is capable of inhibiting a reaction at the interface between a sulfide-based solid electrolyte and the positive electrode active material. A positive electrode active material particle for sulfide-based all-solid-state batteries, the surface of which is reformed, using the method and a sulfide-based all-solid-state battery, the charge/discharge characteristics of which are improved, including the same are also disclosed. The positive electrode active material particle for sulfide-based all-solid-state batteries manufactured using a dry-type method exhibits larger capacity than a positive electrode active material particle for sulfide-based all-solid-state batteries manufactured through a conventional wet-type process. In addition, the manufacturing process is simplified, and the amount of byproducts is reduced.

A fuel cell electrolyte includes a nitrogen-doped phosphate tetrahedral network having a plurality of linked tetrahedra, each of the plurality of the linked tetrahedra having a phosphorus cation center and four anions including oxygen or nitrogen, the network having at least one compound of formula (I):
H.sub.3+xPO.sub.4−xN.sub.x
where x is any number between 0.001 and 3.

A solid electrolyte material contains Li, M, and X. M contains Y, and X is at least one selected from the group consisting of Cl, Br, and I. A first converted pattern, which is obtained by converting the X-ray diffraction pattern of the solid electrolyte material to change its horizontal axis from the diffraction angle to q, includes its base peak within the range in which q is 2.109 Å.sup.−1 or more and 2.315 Å.sup.−1 or less. A second converted pattern, which is obtained by converting the X-ray diffraction pattern to change its horizontal axis from the diffraction angle to q/q.sub.0, where q.sub.0 is the q corresponding to the base peak in the first converted pattern, includes a peak within each of the range in which q/q.sub.0 is 1.28 or more and 1.30 or less and the range in which q/q.sub.0 is 1.51 or more and 1.54 or less.

According to one embodiment, a separator is provided. The separator includes a composite membrane. The composite membrane includes a substrate layer, a first composite layer, and a second composite layer. The first composite layer is located on one surface of the substrate layer. The second composite layer is located on the other surface of the substrate layer. The composite membrane has a coefficient of air permeability of 1×10.sup.−14 m.sup.2 or less. The first composite layer has a first surface and a second surface. The first surface is in contact with the substrate layer. The second surface is located on an opposite side to the first surface. Denseness of a portion including the first surface is lower than denseness of a portion including the second surface in the first composite layer.