To provide an electrode composite material capable of exhibiting a high battery capability, containing a particular crystalline sulfide solid electrolyte and an electrode active material, and a method for producing an electrode composite material, including; firstly mixing a raw material inclusion containing at least one kind of a lithium element, a sulfur element, and a phosphorus element, with a complexing agent, so as to form an electrolyte precursor; heating to decomplex the electrolyte precursor; and secondly mixing a decomplexed material obtained through the decomplexing, with an electrode active material.

A standalone lithium ion-conductive sulfide solid electrolyte can include a freestanding inorganic vitreous sheet of sulfide-based lithium ion conducting glass capable of high performance in a lithium metal battery by providing a high degree of lithium-ion conductivity while being highly resistant to the initiation and/or propagation of lithium dendrites. Such an electrolyte is also itself manufacturable, and readily adaptable for battery cell and cell component manufacture, in a cost-effective, scalable manner. Methods of making and using the electrolyte, and battery cells and cell components incorporating the electrolyte are also disclosed.

There is provided an inorganic solid electrolyte-containing composition containing an inorganic solid electrolyte, binder particles having an average particle diameter of 10 to 1,000 nm, and a dispersion medium, in which a block polymer is contained to constitute the binder particles, this block polymer contains a block polymerized chain which has a terminal block chain having a C Log P value of 2 or more and having a specific constitutional component and has a block chain having a C Log P value of 1 or less, the block chain being adjacent to this terminal block chain. There are also provided a sheet for an all-solid state secondary battery and an all-solid state secondary battery, and manufacturing methods for a sheet for an all-solid state secondary battery and an all-solid state secondary battery.

Electrolytes, methods of preparing electrolytes, and batteries include electrolytes. Electrolytes may include a material of formula (I), Li.sub.3PS.sub.4-xO.sub.x, wherein x is 0<x≤1. The electrolytes may be glass-ceramic electrolytes. Batteries including electrolytes may be lithium-ion batteries.

A sulfide-based solid electrolyte contains a nickel (Ni) element and a halogen element. For example, a sulfide-based solid electrolyte can include, with respect to 100 parts by mole of a mixture of lithium sulfide (Li.sub.2S) and diphosphorus pentasulfide (P.sub.2S.sub.5), 5 parts by mole to 20 parts by mole of nickel sulfide (Ni.sub.3S.sub.2), and 5 parts by mole to 40 parts by mole of lithium halide.

A sulfide-based solid electrolyte contains a nickel (Ni) element and a halogen element. For example, a sulfide-based solid electrolyte can include, with respect to 100 parts by mole of a mixture of lithium sulfide (Li.sub.2S) and diphosphorus pentasulfide (P.sub.2S.sub.5), 5 parts by mole to 20 parts by mole of nickel sulfide (Ni.sub.3S.sub.2), and 5 parts by mole to 40 parts by mole of lithium halide.

To provide an electrolyte membrane that exhibits high proton conductivity even at low humidity, the electrolyte membrane includes a composite membrane including: a microporous polyolefin membrane that has an average pore diameter of 1 to 1000 nm and a porosity of 50 to 90% and that can be impregnated with a solvent having a surface free energy of 28 mJ/m.sup.2 or more, and an electrolyte containing a perfluorosulfonic acid polymer having an EW of 250 to 850 loaded into the pores of the microporous polyolefin membrane, wherein the membrane thickness of the composite membrane is 1 to 20 μm.

To provide an electrolyte membrane that exhibits high proton conductivity even at low humidity, the electrolyte membrane includes a composite membrane including: a microporous polyolefin membrane that has an average pore diameter of 1 to 1000 nm and a porosity of 50 to 90% and that can be impregnated with a solvent having a surface free energy of 28 mJ/m.sup.2 or more, and an electrolyte containing a perfluorosulfonic acid polymer having an EW of 250 to 850 loaded into the pores of the microporous polyolefin membrane, wherein the membrane thickness of the composite membrane is 1 to 20 μm.

It is an object of the invention to provide sulfide solid electrolytes having good processability at the time of manufacturing a battery and high ionic conductivity. The present invention relates to a sulfide solid electrolyte containing lithium, phosphorus and sulfur, having a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peak B at 29.7±0.5 deg in powder X-ray diffraction using CuKα rays, and the half-value width of at least one peak obtained by separating the peaks observed in a range of 60 to 120 ppm in solid-state .sup.31P-NMR measurements is 500 to 800 Hz.

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.