A class of compositions that are inclusive of a lithium metal oxide or oxyfluoride compound having a general formula: LiTM[n]OF where TM[n] represents a number of transition metal species inclusive of transitional metal species differentiated by charge or d.sup.0 electron shell conformation, with [n] being at least 4 of said transitional metal species, and wherein said lithium metal oxide or oxyfluoride has a cation-disordered rocksalt (DRX) structure and a mitigated SRO via a high entropy DRX design strategy. Also featured is a method of synthesizing the high entropy DRX lithium metal oxide or oxyfluoride compounds, as well as usage of the same in Li-ion batteries, with particular utility in cathodes of such Li-ion batteries.

A niobic acid aqueous solution is provided having higher dispersibility than an ammonium niobate sol and having better solubility than a complex salt of niobic acid. The niobic acid aqueous solution contains 0.1 to 40 mass % of niobium in terms of Nb.sub.2O.sub.5, wherein no particles of 1.0 nm or more are detected in the particle size distribution measurement using dynamic light scattering. A method for producing the same includes adding a niobium fluoride aqueous solution containing 1 to 100 g/L of niobium in terms of Nb.sub.2O.sub.5 to an ammonia aqueous solution having an ammonia concentration of 20 to 30 mass % and reacting them, removing fluorine from the obtained reaction solution, and adding at least one selected from amines and ammonia to the obtained solution and reacting them.

A niobic acid aqueous solution is provided having higher dispersibility than an ammonium niobate sol and having better solubility than a complex salt of niobic acid. The niobic acid aqueous solution contains 0.1 to 40 mass % of niobium in terms of Nb.sub.2O.sub.5, wherein no particles of 1.0 nm or more are detected in the particle size distribution measurement using dynamic light scattering. A method for producing the same includes adding a niobium fluoride aqueous solution containing 1 to 100 g/L of niobium in terms of Nb.sub.2O.sub.5 to an ammonia aqueous solution having an ammonia concentration of 20 to 30 mass % and reacting them, removing fluorine from the obtained reaction solution, and adding at least one selected from amines and ammonia to the obtained solution and reacting them.

Provided are a coated active material having excellent properties that can reduce the reaction resistance of a battery, and a method for producing a coated active material that can achieve both a high processing speed and high processing quality. The method for producing a coated active material includes: mixing an electrode active material and a coating solution containing Li and an element M and having a surface energy of 72 mN/m or less to prepare a slurry; and drying the slurry in an air flow and thereby causing a Li-containing oxide to adhere to at least a portion of the surface of the electrode active material, to obtain a coated active material, where the element M is at least one element selected from Nb, F, Fe, P, Ta, V, Ge, B, Al, Ti, Si, W, Zr, Mo, S, Cl, Br, and I.

Provided are a coated active material having excellent properties that can reduce the reaction resistance of a battery, and a method for producing a coated active material that can achieve both a high processing speed and high processing quality. The method for producing a coated active material includes: mixing an electrode active material and a coating solution containing Li and an element M and having a surface energy of 72 mN/m or less to prepare a slurry; and drying the slurry in an air flow and thereby causing a Li-containing oxide to adhere to at least a portion of the surface of the electrode active material, to obtain a coated active material, where the element M is at least one element selected from Nb, F, Fe, P, Ta, V, Ge, B, Al, Ti, Si, W, Zr, Mo, S, Cl, Br, and I.

A method for preparing a niobium, titanium or vanadium metal oxide nanostructured material is provided. The method comprises providing an aqueous reagent comprising (i) a soluble metal oxalate, and/or (ii) oxalic acid and a metal oxide precursor, adding a buffering agent to the aqueous reagent to form a mixture, and heating the mixture under hydrothermal conditions to obtain the metal oxide nanostructured material. The metal oxide nanostructured material may also be doped with a dopant metal such as titanium to enhance capacity and cycling stability. An electrode comprising the metal oxide nanostructured material, and an electrochemical cell containing the electrode are also provided.

A method for preparing a niobium, titanium or vanadium metal oxide nanostructured material is provided. The method comprises providing an aqueous reagent comprising (i) a soluble metal oxalate, and/or (ii) oxalic acid and a metal oxide precursor, adding a buffering agent to the aqueous reagent to form a mixture, and heating the mixture under hydrothermal conditions to obtain the metal oxide nanostructured material. The metal oxide nanostructured material may also be doped with a dopant metal such as titanium to enhance capacity and cycling stability. An electrode comprising the metal oxide nanostructured material, and an electrochemical cell containing the electrode are also provided.

The present invention relates to a chalcogenide device and particularly to a metal chalcogenide device using transition metal chalcogenides as electrodes and a production method therefor. The metal chalcogenide device according to the present invention may comprise: a substrate; an oxide layer positioned on the substrate; a first conductive metal chalcogenide layer positioned on the oxide layer; and first and second electrodes, which are positioned apart from one another on the metal chalcogenide layer and comprise metal chalcogenides.

There is provided a secondary battery including a cathode, an anode including an anode active material layer and a coating film, and an electrolytic solution. The anode active material layer includes a titanium-containing compound, and a surface of the anode active material layer is coated with the coating film. The electrolytic solution includes one or more of unsaturated cyclic carbonate esters. Porosity of a portion of the anode active material layer measured with use of a mercury intrusion technique is within a range from 30% to 50% both inclusive. The portion of the anode active material layer is cut together with a portion of the coating film from a surface of the coating film to a depth of 10 μm.

A solid electrolyte material contains Li, M, and X. M is at least one selected from metallic elements, and X is at least one selected from the group consisting of Cl, Br, and I. A plurality of atoms of X form a sublattice having a closest packed structure. An average distance between two adjacent atoms of X among the plurality of atoms of X is 1.8% or more larger than a distance between two adjacent atoms of X in a rock-salt structure composed only of Li and X.