Provided are a sodium ion-conductive crystal-containing solid electrolyte sheet capable of giving excellent battery characteristics even when reduced in thickness, and an all-solid-state battery using the same. The solid electrolyte sheet contains at least one type of sodium ion-conductive crystal selected from β″-alumina and NASICON crystal and has a thickness of 500 μm or less and a flatness of 200 μm or less.

Disclosed herein are systems and methods from processing flue gas desulfurization (FGD) gypsum feedstock and ash feedstocks, either separately or together. FGD gypsum conversion comprises reacting FGD gypsum (calcium sulfate) feedstock or phosphogypsum, in either batch or continuous mode, with ammonium carbonate reagent to produce commercial products comprising ammonium sulfate and calcium carbonate. A process to separate the impurities and convert the calcium carbonate to a pure precipitated calcium carbonate is disclosed. These impurities include a concentrate of valuable Rare Earth Elements, and radioactive thorium and uranium. A process to convert calcium sulfite to calcium sulfate using oxygen and a catalyst is also disclosed. Ash conversion comprises a leach process followed by a sequential precipitation process to selectively precipitate products at predetermined pHs resulting in metal hydroxides which may be converted to oxides or carbonates. The processes may be controlled by use of one or more processors.

Disclosed herein are systems and methods from processing flue gas desulfurization (FGD) gypsum feedstock and ash feedstocks, either separately or together. FGD gypsum conversion comprises reacting FGD gypsum (calcium sulfate) feedstock or phosphogypsum, in either batch or continuous mode, with ammonium carbonate reagent to produce commercial products comprising ammonium sulfate and calcium carbonate. A process to separate the impurities and convert the calcium carbonate to a pure precipitated calcium carbonate is disclosed. These impurities include a concentrate of valuable Rare Earth Elements, and radioactive thorium and uranium. A process to convert calcium sulfite to calcium sulfate using oxygen and a catalyst is also disclosed. Ash conversion comprises a leach process followed by a sequential precipitation process to selectively precipitate products at predetermined pHs resulting in metal hydroxides which may be converted to oxides or carbonates. The processes may be controlled by use of one or more processors.

Disclosed is an apparatus and method for generating hydrogen from water and recycled soft metals (e.g., used empty aluminum beverage cans). The generated hydrogen can be used as an energy source, for example to power hydrogen fuel cell powered automobiles or to generate electricity for an electrical power grid. The apparatus has a size and weight allowing it to be used where the recycled metal cans are generated, and is suitable for use as a home appliance.

Disclosed is an apparatus and method for generating hydrogen from water and recycled soft metals (e.g., used empty aluminum beverage cans). The generated hydrogen can be used as an energy source, for example to power hydrogen fuel cell powered automobiles or to generate electricity for an electrical power grid. The apparatus has a size and weight allowing it to be used where the recycled metal cans are generated, and is suitable for use as a home appliance.

The present invention provides a secondary battery-use active material that allows for an improvement in thermal stability after charge and discharge are repeated. The secondary battery-use active material of the present invention includes a cathode active material that includes (A) a main phase and a sub-phase, (B) the main phase containing a first lithium compound represented by Li.sub.aNi.sub.bM.sub.cAl.sub.dO.sub.e (where M is an element such as cobalt, and 0.8<a<1.2, 0.45≦b≦1, 0≦c≦1, 0≦d≦0.2, 0<e≦1.98, (c+d)>0, and (b+c+d)≦1), and (C) the sub-phase containing a second lithium compound that contains lithium, aluminum, and oxygen as constituent elements.

The purpose of the present invention is to provide an industrially advantageous method for producing α-lithium aluminate which has physical properties that are suitable for use as an electrolyte holding plate of a MCFC having excellent thermal stability, even if the α-lithium aluminate is a fine material having a BET specific surface area of 10 m.sup.2/g or higher in particular. Provided is a method for producing α-lithium aluminate characterized by subjecting a mixture (a), which is obtained by mixing transitional alumina and lithium carbonate at an Al/Li molar ratio of 0.95-1.01, to a first firing reaction so as to obtain a fired product, and subjecting a mixture (b), which is obtained by adding an aluminum compound to the obtained fired product at quantities whereby the molar ratio of aluminum atoms in the aluminum compound relative to lithium atoms in the fired product (Al/Li) is 0.001-0.05, to a second firing reaction.

The present invention provides an abrasive comprising α-alumina particles having a polyhedral crystal structure, wherein the α-alumina particles have an average diameter (D50) of 300 nm to 10 μm and a bulk density of 0.2-0.5 g/mL, a [0001] face in the crystal structure of the α-alumina particles occupies 10-20% on the basis of the total crystal face area, and the amount of α-alumina particles is 85-100 wt % on the basis of the total weight. The abrasive of the present invention comprises α-alumina particles satisfying predetermined particle size and density ranges while having a polyhedral crystal structure, and thus provides excellent dispersibility in a polishing slurry to enable a polishing rate to increase, while minimizing scratch formation during polishing.

The present invention provides an abrasive comprising α-alumina particles having a polyhedral crystal structure, wherein the α-alumina particles have an average diameter (D50) of 300 nm to 10 μm and a bulk density of 0.2-0.5 g/mL, a [0001] face in the crystal structure of the α-alumina particles occupies 10-20% on the basis of the total crystal face area, and the amount of α-alumina particles is 85-100 wt % on the basis of the total weight. The abrasive of the present invention comprises α-alumina particles satisfying predetermined particle size and density ranges while having a polyhedral crystal structure, and thus provides excellent dispersibility in a polishing slurry to enable a polishing rate to increase, while minimizing scratch formation during polishing.

The disclosure provides a potassium aluminate phosphor which is doped with Mn+ or with Eu+ and Mn+, a lighting device, and methods for making the same. This disclosure also provides a conversion light emitting diode (LED) including a semiconductor layer sequence set up to emit electromagnetic primary radiation; and a conversion element including an Mn.sup.2+-doped potassium aluminate phosphor or an Eu.sup.2+- and Mn.sup.2+-doped potassium aluminate phosphor and at least partly converts the electromagnetic primary radiation to electromagnetic secondary radiation, wherein the Mn.sup.2+-doped potassium aluminate phosphor or the Eu.sup.2+- and Mn.sup.2+-doped potassium aluminate phosphor has a general empirical formula K.sub.xAl.sub.11+yO.sub.17+z:Mn.sup.2+, or K.sub.xAl.sub.11+yO.sub.17+z:(Mn.sup.2+,Eu.sup.2+).