In an aspect, a Co.sub.2Z ferrite has the formula: (Ba.sub.1-xSr.sub.x).sub.3Co.sub.2+yM.sub.yFe.sub.24-2y-zO.sub.41. M is at least one of Mo, Ir, or Ru. The variable x can be 0 to 0.8, or 0.1 to 0.8. The variable y can be 0 to 0.8, or 0.01 to 0.8. The variable z can be −2 to 2. The Co.sub.2Z ferrite can have an average grain size of 5 to 100 nanometers, or 30 to 80, or 10 to 40 nanometers as measured using at least one of transmission electron microscopy, field emission scanning electron microscopy, or x-ray diffraction.

A CoVO.sub.x composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVO.sub.x having pores with average diameters of 2-200 nm. The method of making the composite electrode involves contacting the substrate with an aerosol comprising a solvent, a cobalt complex, and a vanadium complex. The CoVO.sub.x composite electrode is capable of being used in an electrochemical cell for water oxidation.

A CoVO.sub.x composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVO.sub.x having pores with average diameters of 2-200 nm. The method of making the composite electrode involves contacting the substrate with an aerosol comprising a solvent, a cobalt complex, and a vanadium complex. The CoVO.sub.x composite electrode is capable of being used in an electrochemical cell for water oxidation.

Provided are a positive active material for a lithium secondary battery, a method of preparing the positive active material, a positive electrode for a lithium secondary battery including the positive active material, and a lithium secondary battery including a positive electrode including the positive active material, in which the positive active material may include a nickel-based lithium metal oxide secondary particle including a plurality of large primary particles, the nickel-based lithium metal oxide secondary particle may have a hollow structure having a pore inside, a size of each of the large primary particles may be in a range of about 2 micrometers (μm) to about 6 μm, and a size of the nickel-based lithium metal oxide secondary particle may be in a range of about 10 μm to about 18 μm.

Techniques including methods and apparatuses for selective measurement and monitoring of halide concentrations in processing solutions for iron triad metals and their alloys are provided. Methods include monitoring of a halide ion, for example, based on a first analytical method such as conductivity with a compensation of the results for a main metal concentration such as a second analytical measurement of concentration of an iron triad metal (e.g., nickel (Ni)). From such measurements, a concentration of certain halide ions can be selectively determined.

Provided are a battery-level Ni—Co—Mn mixed solution and a preparation method for a battery-level Mn solution, the steps thereof comprising: acid dissolution (S1), alkalization to remove impurities (S2), synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), synergistic extraction (S5), and refining extraction (S6).

The steps of deep ageing to remove impurities (S4) and synergistic extraction (S5) comprise: performing deep ageing on a filtrate obtained from the step of synchronous precipitation of calcium, magnesium, and lithium (S3), and after performing filtration to remove impurities, obtaining an aged filtrate; using P204 to extract the aged filtrate and obtain a loaded organic phase, and subjecting the loaded organic phase to staged back-extraction to obtain the battery-level Ni—Co—Mn mixed solution and a Mn-containing solution. By means of the cooperation between the multiple process steps of synchronous precipitation of calcium, magnesium, and lithium (S3), deep ageing to remove impurities (S4), and synergistic extraction (S5), the impurity content of the obtained battery-level Ni—Co—Mn mixed solution is significantly lowered, and the battery-level Ni—Co—Mn mixed solution can be directly used to prepare a lithium battery ternary precursor material. At the same time, the battery-level Mn solution can also be obtained, which is favorable for large-scale applications of the process and increasing economic benefits.

The invention provides an air electrode material powder for solid oxide fuel cells, comprising particles of a perovskite composite oxide represented by the general formula ABO3, and comprising La and Sr as the A-site elements, and Co and Fe as the B-site elements.

Process for making a manganese composite (oxy)hydroxide with a mean particle diameter D50 in the range from 2 to 16 μm comprising the step(s) of combining (a) an aqueous solution containing salts of nickel and of manganese, and, optionally, at least one of Al, Mg, or transition metals other than nickel and manganese wherein at least 50 mole-% of the metal is manganese, (b) with an aqueous solution of an alkali metal hydroxide and (c) an organic acid or its alkali or ammonium salt wherein said organic acid bears at least two functional groups per molecule and at least one of the functional groups is a carboxylate group.

A positive electrode active material that has high capacity and excellent charge and discharge cycle performance for a secondary battery is provided. The positive electrode active material includes a group of particles including a first group of particles and a second group of particles. The group of particles includes lithium, cobalt, nickel, aluminum, magnesium, oxygen, and fluorine. When the number of cobalt atoms included in the group of particles is taken as 100, the number of nickel atoms is greater than or equal to 0.05 and less than or equal to 2, the number of aluminum atoms is greater than or equal to 0.05 and less than or equal to 2, and the number of magnesium atoms is greater than or equal to 0.1 and less than or equal to 6. When particle size distribution in the group of particles is measured by a laser diffraction and scattering method, the first group of particles has a first peak and the second group of particles has a second peak; the first peak has a local maximum value at longer than or equal to 2 μm and shorter than or equal to 4 μm, and the second peak has a local maximum value at longer than or equal to 9 μm and shorter than or equal to 25 μm.

A method for forming a sintered composition including providing a slurry precursor including a lithium-, sodium-, or magnesium-based compound; tape casting the slurry precursor to form a green tape; and sintering the green tape at a temperature in a range of 500° C. to 1350° C. for a time in a range of less than 60 min to form a sintered composition, such that the slurry precursor further includes a solvent and dispersant. The dispersant may include an amine compound, a carboxylic acid compound, or combinations, mixtures, or salts thereof.