A positive electrode active material for a lithium ion secondary battery has a rock salt type structure represented by General Formula:

Li.sub.xTi.sub.2x-1Mn.sub.2-3xO (0.50<x<0.67)(1)

and has an average particle size of 0.5 m or less.

A magnetic magnesium-manganese layered double metal oxide composite and preparation and application. A soluble magnesium salt and a soluble manganese salt are dissolved in water to obtain a magnesium-manganese salt complex liquid; and a soluble carbonate and a soluble hydroxide are dissolved in water to obtain a carbonate-hydroxide complex liquid; a ferroferric oxide powder is added to the carbonate-hydroxide complex liquid, and then ethanol is added for ultrasonic dispersion to obtain a dispersion liquid; then the magnesium-manganese salt complex liquid is added for aging, centrifuging, washing, drying, grinding for sieving, and calcinating at 250-550? C. to obtain a magnetic magnesium-manganese layered double metal oxide composite. The composite of the present invention has relatively strong magnetism to Cd removal, and is featured by high adsorption efficiency, rapid adsorption rate and stability. Moreover, the composite can not only immobilize Cd efficiently, but also can be separated and recycled by magnet.

High-temperature thermochemical energy storage materials using doped magnesium-transition metal spinel oxides are provided. -transition metal spinel oxides, such as magnesium manganese oxide (MgMn).sub.3O.sub.4, are promising candidates for high-temperature thermochemical energy storage applications. However, the use of these materials has been constrained by the limited extent of their endothermic reaction. Embodiments described herein provide for doping magnesium-transition metal spinel oxides to produce a material of low material costs and with high energy densities, creating an avenue for plausibly sized modules with high energy storing capacities.

Provided is a novel lithium complex oxide containing molybdenum. A complex oxide represented by the following compositional formula: Li.sub.xM.sub.yMo.sub.zO wherein M is one or two or more selected from the group consisting of Mn, Ru, Sn, Mg, Al, Ti, V, Cr, Fe, Co, Ni, Cu, and Zn; x is in the range of 0.60 to 0.75; y is in the range of 0.15 to 0.25; and z is in the range of 0.075 to 0.20.

A convenient and versatile method for preparing complex metal oxides is disclosed. The method uses a low temperature, environmentally friendly gel-collection method to form a single phase nanomaterial. In one embodiment, the nanomaterial consists of Ba.sub.AMn.sub.BTi.sub.CO.sub.D in a controlled stoichiometry.

A positive electrode active material includes secondary particles. The secondary particles include a plurality of primary particles. The primary particles include a lithium-containing composite metal oxide. Inside the secondary particles, an electron conducting oxide is disposed at at least a part of a grain boundary between the primary particles. The electron conducting oxide has a perovskite structure.

The disclosure relates to a method for removing sulfur-containing compounds from a fluid. The method involves adding manganese oxide to the fluid; doping the manganese oxide in situ with iron, cobalt, or combinations thereof to give a doped manganese oxide adsorbent; and contacting the fluid with a selected amount of the doped manganese oxide adsorbent and at a selected temperature and pressure sufficient for the doped manganese oxide adsorbent to preferentially adsorb the sulfur-containing compounds in the fluid. The disclosure also relates to a process for preparing a doped manganese oxide adsorbent, and a doped manganese oxide adsorbent prepared by the process. The disclosure further relates to a method for tuning structural properties (e.g., surface area, pore size and pore volume) of a doped manganese oxide adsorbent.

Process for the fabrication of an electrode structure comprising an electrochemically active material suitable for use in an energy storage device. The method includes electrodepositing the electrochemically active material onto an electrode in electrodeposition bath containing a non-aqueous electrolyte. The electrode structure can be used for various applications such as electrochemical energy storage devices including high power and high-energy lithium-ion batteries.

Preparation, characterization, and an electrochemical study of Mg0.1V2O5 prepared by a novel sol-gel method with no high-temperature post-processing are disclosed. Cyclic voltammetry showed the material to be quasi-reversible, with improved kinetics in an acetonitrile-, relative to a carbonate-, based electrolyte. Galvanostatic test data under a C/10 discharge showed a delivered capacity >250 mAh/g over several cycles. Based on these results, a magnesium anode battery, as disclosed, would yield an average operating voltage 3.2 Volts with an energy density 800 mWh/g for the cathode material, making the newly synthesized material a viable cathode material for secondary magnesium batteries.

A catalyst carrier may include an aluminate based body and may have a specific surface area of not greater than about 20 m.sup.2/g. The aluminate based body may include a hexaaluminate phase.