A positive electrode active material for a sodium secondary battery includes a sodium composite transition metal oxide represented by Formula 1 and having a P3 crystal structure, and a positive electrode and a sodium secondary battery which include the positive electrode active material.
Na.sub.x[Li.sub.aM.sub.1-a]O.sub.2  [Formula 1]
wherein M is at least one transition metal, 0.64≤x≤0.7, and 0.01≤a≤0.1.

The present invention relates to a method of producing an iron containing compound, iron containing precursor, or iron containing aqueous solution comprising the steps of: providing direct reduced iron; dissolving the direct reduced iron in organic and/or inorganic acids to provide an iron containing aqueous solution, wherein insoluble impurities of the direct reduced iron are maintained in solid form throughout the dissolution process, to obtain an iron containing aqueous solution with suspended insoluble impurities; separating the said insoluble impurities from the iron containing aqueous solution obtaining a purified iron containing aqueous solution; and optionally solidifying said purified iron containing aqueous solution to provide the iron containing compound or iron containing precursor, by drying.

The present invention further relates to iron containing compounds, iron containing precursors, and iron containing aqueous solutions, and their use in battery components.

The present invention relates to a method of producing an iron containing compound, iron containing precursor, or iron containing aqueous solution comprising the steps of: providing direct reduced iron; dissolving the direct reduced iron in organic and/or inorganic acids to provide an iron containing aqueous solution, wherein insoluble impurities of the direct reduced iron are maintained in solid form throughout the dissolution process, to obtain an iron containing aqueous solution with suspended insoluble impurities; separating the said insoluble impurities from the iron containing aqueous solution obtaining a purified iron containing aqueous solution; and optionally solidifying said purified iron containing aqueous solution to provide the iron containing compound or iron containing precursor, by drying.

The present invention further relates to iron containing compounds, iron containing precursors, and iron containing aqueous solutions, and their use in battery components.

This invention relates to safe immobilization and disposal of arsenic found in industrial waste streams and residues in the form of clean and compact well grown scorodite solids.

Described herein is a method for producing ferrite nanocrystals. The method includes providing a solution including a fatty acid, an aliphatic amine and an alcoholic solvent, adding at least one organometallic precursor compound including a metal selected from the group consisting of Fe, Mn, Co and Zn and an aromatic organic molecule to the solution thereby obtaining a reaction mixture, transferring the reaction mixture to a sealed reactor, thereby obtaining a filling percentage of the sealed reactor between 20 and 70 vol. %, and heating the sealed reactor to a temperature between 160° C. and 240° C. for at least 3 hours.

An organometallic compound, which enables thin-film deposition through vapor deposition, and particularly to a Co or Fe precursor, which is suitable for use in atomic layer deposition or chemical vapor deposition, and a method of preparing the same.

Disclosed herein are electrolyte bismuth calcium ferrites having high oxygen vacancy ion mobility. There can be provided an oxygen vacancy electrolyte material including bismuth calcium ferrites (Bi.sub.1-xCa.sub.xFeO.sub.3-δ).

The present invention discloses a method of preparing an electrode material for lithium-ion batteries comprising the steps of preparing a mixture of precursors taken in predefined stoichiometric ratios for synthesis of lithium iron phosphate (LiFePO4), adding niobium pentoxide as a precursor for doping of niobium at Li+ site of LiFePO.sub.4 for synthesis of niobium doped LiFePO.sub.4 and ball milling operation provides nano sized powder particles. Now, a precursor of carbon is added to said mixture of precursors for synthesizing and obtaining carbon coated niobium doped LiFePO.sub.4 nano sized powder particles. Pellets of required size are prepared and sintered. The obtained pellets are structurally characterized.

A method for efficiently preparing ferrate based on nascent state interfacial activity. The method is as follows: (a) preparing nascent iron solution; (b) adding an oxidizing agent to the iron solution of step (a); (c) adding alkali solution or alkali particles to the mixed solution of step (b), mixing by stirring, and carrying out solid-liquid separation; (d) adding a stabilizing agent to the liquid separated out in step (c), and thus obtaining ferrate solution. The yield is 78-98%. The prepared ferrate solution is stable and can be stored for 3-15 days.

A combined remediation method of petroleum-contaminated soil includes: impurity removal pretreatment, photocatalytic pre-oxidation, stepwise thermal desorption of petroleum from soil, and high-temperature oxidation; with iron-titanium composite metal oxide (ITCMO) as a catalyst, conducting oxidation pretreatment under light conditions so that some cross-linked structures in macromolecular petroleum contaminants are broken and degraded; and conducting stepwise pyrolysis to achieve a removal rate of more than 98.00%. The new method adopts a combined remediation technology of photocatalytic pre-oxidation-stepwise pyrolysis, which realizes a relatively-high removal rate of petroleum hydrocarbons and the efficient and harmless remediation of high-concentration petroleum-contaminated soil, and remedied soil can be reused.