An objective of the present invention is to provide an all-solid-state battery with a high discharge capacity in which lithium vanadium phosphate is used as a positive electrode active material layer and a negative electrode active material layer. According to the present invention, the positive electrode active material layer and the negative electrode active material layer of the all-solid-state battery having an all-solid-state electrolyte between a pair of electrodes contain the lithium vanadium phosphate, the lithium vanadium phosphate contains a polyphosphate compound containing Li and V, and the lithium vanadium phosphate contains Li.sub.3V.sub.2(PO.sub.4).sub.3 as a main phase and contains 1.0% by weight or more and 15.0% by weight or less of Li.sub.3PO.sub.4 relative to Li.sub.3V.sub.2(PO.sub.4).sub.3, whereby a high discharge capacity can be provided.

Disclosed is a method of manufacturing a solid electrolyte using water as a solvent. The method includes dissolving a precursor in water to form a slurry, drying the slurry to form granules, pressing the granules to form a pressed solid body, and sintering the pressed solid body to manufacture a solid electrolyte.

A positive active material made of carbon-coated lithium iron phosphate includes a lithium iron phosphate substrate, and a carbon coating layer on a surface of the substrate. The lithium iron phosphate substrate has a general structural formula LiFe.sub.1-aM.sub.aPO.sub.4, where M is at least one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb, or Ti, and 0≤a≤0.01. A carbon coating factor of the carbon-coated lithium iron phosphate,

[00001]$\eta =\frac{\mathrm{BET}1}{\mathrm{BET}2},$

satisfies 0.81≤η≤0.95, where BET1 denotes a specific surface area of mesopore and macropore structures in the carbon-coated lithium iron phosphate, and BET2 denotes a total specific surface area of the carbon-coated lithium iron phosphate.

A positive active material made of carbon-coated lithium iron phosphate includes a lithium iron phosphate substrate, and a carbon coating layer on a surface of the substrate. The lithium iron phosphate substrate has a general structural formula LiFe.sub.1-aM.sub.aPO.sub.4, where M is at least one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb, or Ti, and 0≤a≤0.01. A carbon coating factor of the carbon-coated lithium iron phosphate,

[00001]$\eta =\frac{\mathrm{BET}1}{\mathrm{BET}2},$

satisfies 0.81≤η≤0.95, where BET1 denotes a specific surface area of mesopore and macropore structures in the carbon-coated lithium iron phosphate, and BET2 denotes a total specific surface area of the carbon-coated lithium iron phosphate.

An all-solid-state battery including: a positive electrode layer that has a positive electrode current collector layer and a positive electrode active material layer; a negative electrode layer that has a negative electrode current collector layer and a negative electrode active material layer; and a solid electrolyte layer that contains a solid electrolyte, in which the positive electrode active material layer and the negative electrode active material layer each have a G-band full-width at half-maximum (G-FWHM) in a Raman spectrum of 40 (cm.sup.−1) or less.

A lithium oxide coated with carbon, wherein the carbon contains co-continuous fibrous carbon having a three-dimensional network structure in which carbon is branched.

A method for forming an insoluble adduct using an acidic medium is provided. A chemical process utilizes acidic media to change the solubility behavior of metal solutes. The method can utilize Group 1 soluble alkali metals but can also be extended to any other soluble salts discussed under the solubility rules. The insoluble salts can be Group 2 alkaline earth metals or other insoluble salts. The insoluble adduct can have the designation XYZ where X is a soluble metal from a metal hydroxide or a metal oxide, Y is an insoluble metal from an insoluble metal hydroxide or an insoluble metal oxide, and Z is the acid ion from an aqueous acidic media.

The present invention relates to a process for preparing an ammonium vanadium phosphate of formula (NH.sub.4)(VO.sub.2)(HPO.sub.4). It also relates to a process for preparing a vanadium orthophosphate VPO.sub.4.

A positive electrode (1) for non-aqueous electrolyte secondary batteries, including a collector (11) and an active material layer (12), wherein a spreading resistance distribution of the layer (12) shows a profile with a sum of frequencies of resistance values 4.0 to 6.0 (logΩ) accounting for 0.0 to 5.0% relative to a total, 100%, of frequencies of resistance values 4.0 to 12.5 (logΩ). A positive electrode (1) for non-aqueous electrolyte secondary batteries, including a collector (11) and an active material layer (12), wherein the layer (12) includes an active material and a conductive carbon material, and an amount of a low-resistance conductive carbon material having a resistivity of 0.10 Ω.Math.cm or less is 0.5% by mass or less, based on a total mass of the layer (12). A positive electrode (1) for non-aqueous electrolyte secondary batteries, including a collector (11) and an active material layer (12), wherein the active material has a coated section including a conductive material, and the layer (12) has a powder resistivity of 10 to 1,000 Ω.Math.cm.

The purpose of the present invention is to provide positive electrode active substance particles for a lithium ion secondary battery, such particles being capable of producing a lithium ion secondary battery having excellent high-speed discharge properties. The present invention is a granulated body of a positive electrode active substance for a lithium ion secondary battery, wherein the primary particle average diameter is 10 to 80 nm and the number of primary particles having a diameter of 100 nm or greater is no more than 5.0%.